What is the Internet?

Internet is a global network that connects billions of computers across the world with each other and to the World Wide Web.
It uses standard internet protocol suite (TCP/IP) to connect billions of computer users worldwide.
It is set up by using cables such as optical fibers and other wireless and networking technologies.
TCP/IP = Transmission Control Protocol/ Internet Protocol.



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Network Vs Internet

Network : A computer network is a group of computers linked to each other that enables the computer to communicate with another computer and share their resources, data, and applications.



The different between Network and Internet:

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NETWORK INTERNET
★ Combination of two or more computer systems. ★ Interconnection of several networks.
★ Limited geographical area in coverage ★ Large geographical area in coverage
★ Note:   Network of Network is known as Internet.



Applications of Internet

Today is the era of Internet applications, today there is a specific application to do every work, using which you can do those tasks very easily. Today we will know in detail about the same applications of the Internet.


★ Communication : Communication is also one of the most used applications of the Internet because today it is very easy to talk through the Internet and today almost everyone is communicating with each other through the Internet. For example, you can talk to someone through chat, you can talk through voice call, you can talk through video call, etc.


★ Job Search : Through these internet job applications, you can find jobs for yourself sitting at home, these job portals have all kinds of jobs for all types of people, all you have to do is use these job applications and just send your resume. Today you can easily find jobs related to your skills through the internet and give a direct interview to HR.


★ Online Shopping : Today the whole world is doing online shopping through the internet, that too sitting at home and you can also shop online from home through the internet. Today there are many such applications on the Internet, through which you can buy anything online. Such as - Mobile, Tablet PC, Computers, Watch, Smart Watch, Television, Fan, Table Fan, LED Bulb, Glasses, Ring, Jewellers, Camera, Home Appliances, clothes, etc.


★ Stock Marketing : In the earlier times, no one knew about the stock market, what is the stock market, but today everyone knows about the stock market, what is the stock market and how to invest money in it. Today many people are earning a lot of money from the stock market, today people know which stock to invest in and when to sell which stock so that more money can be earned. Here we can buy or sell any stock without any broker and can also read the information of stock market moment by moment.


★ E-Banking : Today is the era of e-learning in the present time, e-learning means electronic learning which means you can now study from anywhere through e-learning. If you understand it in an easy language, now you can do your studies by staying in any corner of the world, now you do not need to go to any college or institute to study, You can study from online live class through e-learning sitting at home.





Computer Network Types:


A computer network can be categorized by their area coverage size. A computer network is mainly of four types:


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LAN(Local Area Network)

PAN(Personal Area Network)

MAN(Metropolitan Area Network)

WAN(Wide Area Network)






LAN(Local Area Network)


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1. Local Area Network is a group of computers connected to each other in a small area such as building, office.

2. LAN is used for connecting two or more personal computers through a communication medium such as twisted pair, coaxial cable, etc.

3. It is less costly as it is built with inexpensive hardware such as hubs, network adapters, and ethernet cables.

4. The data is transferred at an extremely faster rate in Local Area Network.

5. Local Area Network provides higher security.




PAN(Personal Area Network)


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1. Personal Area Network is a network arranged within an individual person, typically within a range of 10 meters.

2. Personal Area Network is used for connecting the computer devices of personal use is known as Personal Area Network.

3. Thomas Zimmerman was the first research scientist to bring the idea of the Personal Area Network.

4. Personal computer devices that are used to develop the personal area network are the laptop, mobile phones, media player and play stations.


★ There are two types of Personal Area Network:

1. Wireless Personal Area Network : Wireless Personal Area Network is developed by simply using wireless technologies such as WiFi, Bluetooth. It is a low range network.

2. Wired Personal Area Network : Wired Personal Area Network is created by using the USB and lan cable.




MAN(Metropolitan Area Network)


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1. A metropolitan area network is a network that covers a larger geographic area by interconnecting a different LAN to form a larger network.

2. Government agencies use MAN to connect to the citizens and private industries.

3. In MAN, various LANs are connected to each other through a telephone exchange line.

4. The most widely used protocols in MAN are RS-232, Frame Relay, ATM, ISDN, OC-3, ADSL, etc.

5. It has a higher range than Local Area Network(LAN).



Uses Of Metropolitan Area Network:

1. MAN is used in communication between the banks in a city.

2. It can be used in an Airline Reservation.

3. It can be used in a college within a city.

4. It can also be used for communication in the military.






WAN(Wide Area Network)


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1. A Wide Area Network is a network that extends over a large geographical area such as states or countries.

2. A Wide Area Network is quite bigger network than the MAN and LAN.

3. A Wide Area Network is not limited to a single location, but it spans over a large geographical area through a telephone line, fibre optic cable or satellite links.

4. The internet is one of the biggest WAN in the world.

5. A Wide Area Network is widely used in the field of Business, government, and education.



Network Topology


Network Topology A network topology is the physical and logical arrangement of nodes and connections in a network. Nodes usually include devices such as switches, routers, device and software.

In Other word, Topology defines the structure of the network of how all the components are interconnected to each other.


Types of Network Topology:

Physical topology is the geometric representation of all the nodes in a network. There are six types of network topology which are Bus Topology, Ring Topology, Tree Topology, Star Topology, Mesh Topology, and Hybrid Topology.




Bus Topology

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1. The bus topology is designed in such a way that all the stations are connected through a single cable known as a backbone cable.

2. Each node is either connected to the backbone cable by drop cable or directly connected to the backbone cable.

3. When a node wants to send a message over the network, it puts a message over the network. All the stations available in the network will receive the message whether it has been addressed or not.

4. The bus topology is mainly used in IEEE 802.3 (ethernet) and IEEE 802.4 (IEEE stands for Institute of Electrical and Electronics Engineers) standard networks.

5. The configuration of a bus topology is quite simpler as compared to other topologies.

6. The backbone cable is considered as a "single lane" through which the message is broadcast to all the stations.

7. The most common access method of the bus topologies is CSMA (Carrier Sense Multiple Access).


CSMA: It is a media access control used to control the data flow so that data integrity is maintained, i.e., the packets do not get lost. There are two alternative ways of handling the problems that occur when two nodes send the messages simultaneously.

CSMA CD: CSMA CD (Collision detection) is an access method used to detect the collision. Once the collision is detected, the sender will stop transmitting the data. Therefore, it works on "recovery after the collision".

CSMA CA: CSMA CA (Collision Avoidance) is an access method used to avoid the collision by checking whether the transmission media is busy or not. If busy, then the sender waits until the media becomes idle. This technique effectively reduces the possibility of the collision. It does not work on "recovery after the collision".


Advantages of Bus topology:


1. Low-cost cable: Here, Nodes are directly connected to the cable without passing through a hub. Therefore, the initial cost of installation is low.

2. Moderate data speeds: Coaxial or twisted pair cables are mainly used in bus-based networks that support upto 10 Mbps.

3. Familiar technology: Bus topology is a familiar technology as the installation and troubleshooting techniques are well known, and hardware components are easily available.

4. Limited failure: A failure in one node will not have any effect on other nodes.


Disadvantages of Bus topology:


1. A bus topology is quite simpler, but still it requires a lot of cabling.

2. Bus topology is not great for large networks.

3.If two nodes send the messages simultaneously, then the signals of both the nodes collide with each other.

4. Adding new devices to the network would slow down the network.

5. Need terminators are required at both ends of the main cable.

6. The main disadvantage of bus topology is, if the main cable (backbone cable) is break then whole network is break down.





Ring Topology:

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1. Ring topology is like a bus topology, but with connected ends (i.e., each node is connected to other node and having no termination point).

2. The node that receives the message from the previous computer will retransmit to the next node.

3. If the data flows in one direction, i.e., it is unidirectional in the other hand, if the data flows in two direction, i.e., it is bidirectional

4. The data in a ring topology flow in a clockwise direction (if it is unidirectional).

5. Token passing: It is a network access method in which token is passed from one node to another node (a token is used as a carrier).


Working of Token passing :
(Token: It is a frame that circulates around the network.)

★ Suppose computer A wants to send data to computer D then data is first placed in the packet(here the sender modifies the token by putting the address along with the data) and the packet is transferred to computer B then computer C and finally, to the computer, D. Data is travelling in the form packets in the ring topology. If the data is received in the target node then the token received by the destination device, then it sends the acknowledgment to the sender, the empty packet is passed to the next node until it reaches the source node. The source node will finally know that its data is received successfully.


★ Advantages of Ring Topology

1. FDDI (Fiber Distributed Data Interface) is a standard for data transmission on fiber optic cables. It uses a ring topology to transmit data at high speeds.

2. The possibility of collision is minimum in this type of topology.

3. Cheap to install.

Disadvantages of Ring Topology

1. The failure of a single node in the network can cause the entire network to fail.

2. Troubleshooting is difficult in this topology.

3. The addition of stations in between or the removal of stations can disturb the whole topology.

4. In order for all the computer to communicate with each other, all computer must be turned on.

5. If one workstation shuts down, it affects whole network or if a node goes down entire network goes down.




Star Topology

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1. Star topology is an arrangement of the network in which every node is connected to the central hub or switch.

2. The central computer is known as a server, and the peripheral devices attached to the server are known as clients .

3. Coaxial cable or RJ-45 cables are used to connect the computers.

4. Hubs or Switches are mainly used as connection devices in a physical star topology.

5. Star topology is the most popular topology in network implementation.

6. Star networks require a point-to-point connection between the central node.


Advantages of Star Topology

1. If N devices are connected to each other in a star topology, then the number of cables required to connect them is N. So, it is easy to set up.

2. It is high-performing due to hereno data collisions can occur .

3. Robust in nature.

4. Easy fault detection because the link are often easily identified.

5. No disruptions to the network when connecting or removing devices.


Disadvantages of Star Topology

1. If the concentrator (hub) on which the whole topology relies on if it is fails, then the whole system will crash down.

2. More expensive than linear bus topology due to the value of the connecting devices (network switches).

3. Hub requires more resources and regular maintenance because it’s the central system of star .

4. Extra hardware is required (hubs or switches) which adds to cost.




Tree topology

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1. Tree topology combines the characteristics of bus topology and star topology.

2. A tree topology is a type of structure in which all the computers are connected with each other in hierarchical fashion.

3. The top-most node in tree topology is known as a root node, and all other nodes are the descendants of the root node.

4. In a tree topology, there is one central node (the “trunk”), and each node is connected to the central node through a single path.


Advantages of Tree Topology :

1. The other nodes in a network are not affected if one of their nodes gets damaged or does not work.

2. Tree Topology is reliable.

3. It can support a large number of nodes


Disadvantages of Tree Topology

1. If any fault occurs in the node, then it becomes difficult to troubleshoot the problem.

2. A tree topology mainly relies on main bus cable and failure in main bus cable will damage the overall network.



Mesh topology


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1. There are multiple paths from one computer to another computer.

2. It does not contain the switch, hub or any central computer which acts as a central point of communication.

3.The Internet is an example of the mesh topology.

4. Mesh topology is mainly used for WAN implementations and wireless networks, where communication failures are a critical concern.

5. In this mesh topology, if one link fails, there are alternate routes that can be taken.


Mesh topology can be formed by using the formula:

Number of cables = (n*(n-1))/2;

Where n is the number of nodes that represents the network.


Advantages of Mesh Topology :

1. Failure during a single device won’t break the network.

2. There is no traffic problem as there is a dedicated point to point links for every computer.

3. It provides high privacy and security.

4. This topology has robust features to beat any situation.


Disadvantages of Mesh Topology :

1. Installation is extremely difficult in the mesh.

2. Maintenance needs are challenging with a mesh.

3. If the network is not monitored carefully, then the communication link failure goes undetected.

4. Data must go through multiple nodes to reach its destination, this can result in slower network speeds.







Hybrid Topology

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★ A hybrid topology is a type of network topology that uses two or more differing network topologies.
These topologies can include a mix of bus topology, mesh topology, ring topology, star topology, and tree topology.


Types of Hybrid Topology

1. Star-Bus Hybrid Topology

2. Star-Ring Hybrid Topology

3. Hierarchical Network Topology


Advantages of Hybrid Topology

1. It is extremely flexible.

2. Handles a large volume of traffic.

3. It is scalable because the size can be increased easily.


Disadvantages Hybrid Topology

1. Designing is difficult or complex.

2. It is costly. Due to the infrastructure cost is very high as a hybrid network requires a lot of cabling, network devices, etc.


for more details click this link about Hybrid Topology



History of Internet



1) In 1960s..............

  • Initially in the 1960s, During the time computers were larger in size and not moveable. Information stored in any computer, they had to travel to the location of the computer, magnetic computer tapes that could be transported through the postal system of that time.
  • Alongside, Cold War played a major role in the creation of the internet. The Soviet Union's launch of the Sputnik satellite spurred the U.S. Defense Department or Department of Defense (DoD) to consider ways information could still be disseminated even after a nuclear attack.

2) In 1969....................

  • Advanced Research Projects Agency (ARPA) of US Department of Defense. In the year 1969 , ARPANET was introduced.
  • This system was used to transfer confidential data between the Military. It was the great successful the formation of the ARPANET (Advanced Research Projects Agency Network) , the network that ultimately evolved into what we now know as the Internet. ARPANET was a great success but membership was limited to certain academic and research organizations who had contracts with the Defense Department.
  • Note: The Advanced Research Projects Agency (ARPA) gained a “D” when it was renamed the Defense Advanced Research Projects Agency (DARPA)

3) 1950s-1960s .............

  • The concept of a global communication network can be traced back to the 1960s , with ideas such as J.C.R. Licklider's and Paul Baran's on the vision of a "Galactic Network" work on packet switching .
  • The packet switching technology was essential to the development of ARPANET by the United States Military. Packet switching is a technique for transmitting computer data by splitting it into very short, standardized chunks, attaching routing information to each of these chunks, and transmitting them independently through a computer network.
  • The first ARPANET link was established between the Network Measurement Center at the University of California, Los Angeles (UCLA) and Stanford Research Institute (SRI) 22:30 hours on October 29, 1969. See more about


4) In 1970..............

  • Earlier there wasn’t any standard mechanism for the computer networks that would enable them to communicate with each other.
  • Transfer Control Protocol (TCP/IP) which was developed in 1970.
  • Note: The most popular network protocol in the world, TCP/IP protocol suite , was designed in 1970s by 2 DARPA scientists— Vint Cerf and Bob Kahn, persons most often called the fathers of the Internet.

5) In 1983................

  • January 1, 1983 is considered the official birthday of the Internet. Prior to this, the various computer networks did not have a standard way to communicate with each other.
  • A new communications protocol was established called Transmission Control Protocol/Internet Protocol (TCP/IP) .
  • This allowed different kinds of computers on different networks to "talk" to each other.
  • ARPANET and the Defense Data Network officially changed to the TCP/IP standard on January 1, 1983, hence the birth of the Internet.
  • All networks could now be connected by a universal language.





History of WWW



  • Sir Tim Berners-Lee invented the World Wide Web while at CERN, (European Organization for Nuclear Research, known as CERN).
  • Sir Tim Berners-Lee invented the World Wide Web in 1989. WorldWideWeb was written in Objective-C.
  • Sir Tim is the Founder of World Wide Web Consortium (W3C).
  • In 1990, he developed the first web server, the first web browser, and a document formatting protocol, called Hypertext Markup Language (HTML).
  • After publishing the markup language in 1991, and releasing the browser source code for public use in 1993, many other web browsers were soon developed, with Marc Andreessen's Mosaic (later Netscape Navigator).

Link of First Browser of WWWW : See More

Tim's Computer : See More


Mosaic Browser

  • 1) Creadted By: Marc Andreessen
  • 2) Written : C
  • 3) Mosaic was developed at the NCSA ( National Center for Supercomputing Applications ).
  • 4) Mosaic is the first graphical web browser to display images inline with text instead of in a separate window.
  • 5) It was named for its support of multiple Internet protocols, such as Hypertext Transfer Protocol, File Transfer Protocol, Network News Transfer Protocol, and Gopher.
  • See More about Mosaic
  • See more about History of WWW


Website Address and URL


What is Web address ?

  • 1) The web address contains information about the location of the webpage. It is also known as the URL (uniform resource locator).
  • 2) The web address was developed by Sir Tim Berners-Lee and the URL working group of IETF (Internet Engineering Task Force) in the year 1994. It is a name that points to the location of a particular web page in the internet world.
  • 3) A web address, or a Uniform Resource Locator (URL), is a unique reference that directs you to a specific page like the address of a particular file, directory, photo, video, etc. Every web page on the internet has a unique web address, with the help of which the user accesses those web pages.

Components of a web address

Every web address follows the same format. Let’s use this page’s URL as an example to explore the individual components:


Example:

https://www.wix.com/encyclopedia/web-address/


  • 1) Scheme: It is the protocol that is associated with every URL. It tells the browser what type of address the user is trying to access so that the browser connects correctly.
    The two most common schemes are http and https. This page uses https, meaning it has a secure sockets layer (SSL) certificate.

    Example: https://www.wix.com/encyclopedia/web-address/

  • 2) Domain name: A domain name is the website name correlating with its internet protocol (IP) address. The domain name indicates which connecting server the internet must use to locate the webpage. It also acts as the website’s primary name.

    Example: https://www.wix.com/encyclopedia/web-address/

  • 3) Domain extension: Also referred to as a top-level domain, a domain extension is the letters that follow the domain name. The first-level set of domain names are the top-level domains (TLDs), such as com, info, net, edu, and org, and the country code(.in,.np) are top-level domains.

    Example: https://www.wix.com/encyclopedia/web-address/

  • 4) Path: Path specifies the entire path to a particular web page that the user wants to access or webpage of the primary website the user wants to visit.

    Example: https://www.wix.com/encyclopedia/web-address/

  • 5) Subdomain: A subdomain is a prefix added to a domain name to separate a section of your website. Site owners primarily use subdomains to manage the sections of own content in hierarchy, such as online stores, blogs, job boards or support platforms.

    Example

    https://jobs.example.com/

    https://www.w3school.com/


Note:

  • 1) Parameters: Parameters are the query string that begins with a question mark(?) after the Path. This is the list of key pairs separated by an ampersand(&) sign.
  • 2) Anchor: Anchors are like bookmarks it tell the browser which particular part of a web page the user wants to access. They are written after the Parameters and begin with a hashtag(#).
  • 3) The full domain name may not exceed a total length of 253 ASCII characters in its textual representation.

There are two types of web addresses:

  • 1) Absolute web address: An absolute web address is the web address that contains the domain name and the entire address of the file/directory to which it points. It begins with the protocols like “http”, “https”, “ftp” etc.
  • 2) Relative web address: Relative web address is the web address that can be accessed only if you are on the home page or on any web page of the particular website. Since it is assumed that the user is already present on the website, a relative web address only contains the domain name and the location.





Introduction to IP Address


  • 1) ‘IP’ stands for Internet Protocol, which is the set of rules that makes it possible for devices to communicate over the Internet. With billions of people accessing the Internet every day, unique identifiers are necessary to keep track of who is doing what. The Internet Protocol solves this by assigning IP numbers to every device accessing the Internet.
  • 2) IP is also used for routing and addressing packets of data so that they can travel across networks and arrive at the correct destination. Data traversing the Internet is divided into smaller pieces, called packets. IP information is attached to each packet, and this information helps routers to send packets to the right place.
  • 3) An IP address is a string of numbers separated by periods. IP addresses are expressed as a set of four numbers — an example address might be 192.158.1.38. Each number in the set can range from 0 to 255. So, the full IP addressing range goes from 0.0.0.0 to 255.255.255.255.
  • 4) IP addresses are not random. They are mathematically produced and allocated by the Internet Assigned Numbers Authority (IANA).
  • 5) Each time anyone registers a domain on the internet, they go through a domain name registrar, who pays a small fee to ICANN to register the domain.

Types of IP Address

1) IPv4 (Internet Protocol Version 4)

2) IPv6 (Internet Protocol Version 6)


IPv4 :

  • 1) It stands for Internet Protocol version four. IPv4 was developed by DARPA which is (ARPANET).
  • 2) IPv4 addresses are 32-bit integers having an address space of 232..
  • 3) It is represented by 4 numbers separated by dots in the range of 0-255, which have to be converted to 0 and 1, to be understood by Computers.
  • 4) For Example, An IPv4 Address can be written as 189.123.123.90.

IPv4 Address Format

IPv4 Address Format is a 32-bit Address that comprises binary digits separated by a dot (.).



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IPv6 :

  • 1) IPv6 is based on IPv4 and stands for Internet Protocol version 6.
  • 2) IPv6 was developed by by (IETF) Internet Engineering Task Force.
  • 3) IPv6 is a 128-bits address having an address space of 2128.
  • 4) IPv6 is written as a group of 8 hexadecimal numbers separated by colon (:).

IPv6 Address Format

IPv6 Address Format is a 128-bit IP Address, which is written in a group of 8 hexadecimal numbers separated by colon (:).


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✬ Who manages domain name?

Answer: The Internet Assigned Numbers Authority (IANA) is a department of Internet Corporation for Assigned Names and Numbers (ICANN) that is responsible for maintaining the registries of the Internet's unique identifiers, which include domain names.


✬ On which transport protocol is used the data packets arrive at their destination?

Answer: TCP and UDP.



Domain Name System (DNS)


  • 1) The Domain Name System (DNS) is the phonebook of the Internet.
  • 2) DNS translates domain names to IP addresses so browsers can load Internet resources.
  • 3) DNS servers eliminate the need for humans to memorize IP addresses such as 192.168.1.1 (in IPv4), or more complex newer alphanumeric IP addresses such as 2400:cb00:2048:1::c629:d7a2 (in IPv6).

How DNS Work?

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What Is an Internet Service Provider (ISP)?


  • 1) The term “internet service provider (ISP)” refers to a company that provides access to the internet to both personal and business customers.
  • 2) ISPs make it possible for their customers to surf the web, shop online, conduct business, and connect with family and friends.

List of internet service providers in India.

  • ✬ JIO
  • ✬ VI
  • ✬ Airtel
  • ✬ BSNL

How do ISPs assigned Ip address?

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What are the role of ISP?

  • 1) An internet service provider’s main responsibility is to provide internet access to the companies, families, and individuals that subscribe to their service. This means that they are responsible for ensuring that the transfer of our data through the internet is instant and safely.
  • 2) Depending on the price, an ISP provides subscribers with a certain bandwidth amount and internet speed. Internet service providers can also offer phone and cable television services.
  • 3) An ISP should protect its subscribers from cyber threats and warn them if they are at risk.




Types of Internet Protocol



  • 1) TCP : port number is 22.
    • ✬ It is a connection-oriented protocol (To ensure that, each message reaches its final destination accurately).

  • 2) UDP
    • ✬ User Datagram Protocol (UDP) is a communications protocol for time-sensitive applications like gaming, playing videos, or Domain Name System (DNS) lookups. This allows data to be transferred very quickly, but it can also cause packets to become lost in transit.

  • 3) HTTP: port number is 80
    • ✬ HTTP stands for HyperText Transfer Protocol. It is used to access web pages from a web server.

  • 4) HTTPS: port number is 443
    • ✬ HTTPS stands for HyperText Transfer Protocol Secure. It uses the Secure Socket Layer (SSL) and Transport Layer Security (TLS) protocol. The new version of SSL is TLS(Transport Layer Security)

  • 5) FTP: port number is 21
    • ✬ The File Transfer Protocol is a standard communication protocol, it is a way to download, upload, and transfer files from one location to another on the Internet and between computer systems.

  • 6) SMTP
    • ✬ SMTP stands for Simple Mail Transfer Protocol. It is an Internet standard communication protocol for electronic mail transmission.

  • 7) IMAP
    • ✬ IMAP stands for Internet Message Access Protocol. It is used as the most commonly used protocol for incoming mail.

  • 8) DNS : port number is 53
    • ✬ DNS translates domain names to IP addresses.

  • 9) ARP
    • ✬ ARP stands for Address Resolution Protocol, It finds and translate IP addresses to Physical Addresses (MAC Address).

  • 10) POP3
    • POP stands for Post Office Protocol, It only allows downloading messages from your Inbox to your local computer.
    • Note: POP3 (Post Office Protocol 3) and IMAP (Internet Message Access Protocol) both are MAA (Message accessing agent) , both of these protocols are used to retrieve messages from the mail server to the receivers system.

  • 11) ICMP
    • Internet Control Message Protocol(ICMP) to provide an error control. It is used for reporting errors and management queries.

  • 12) DHCP
    • Dynamic Host Configuration Protocol (DHCP) is a client/server protocol that automatically provides an Internet Protocol (IP) host

  • 13) NAT
    • Network Address Translation (NAT) is the process of translating one or more local IP addresses into one or more global IP addresses, or vice versa, in order to provide Internet access to local hosts.

  • 14) SNMP
    • Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more.




Modes of Connecting Internet:


  • 1) Hotspot:
    • A hotspot is a physical location where people can access the Internet, typically using Wi-Fi, via a wireless local area network (WLAN) with a router connected to an Internet service provider.

  • 2) Wi-Fi:
    • Wifi is also known as Wireless Fidelity. Wi-Fi is a wireless networking technology that permits to connect wirelessly to a network or to other computer or mobile device. A circular radio frequency range is used to transmit data in Wi-Fi. It is known as WLAN. The communication standard is IEEE 802.11.

  • 3) LAN Cable :
    • A LAN cable is a conductor that connects devices in a Local Area Network (LAN) with a network connector. The network cable provides communication between several devices (computers, routers, switches,…). The term “LAN” is an overtake for Ethernet cable.
    • Note: The main RJ45 (Registered Jack-45) is typically used in Ethernets or connecting cable modems with Wi-Fi routers.

  • 4) Broadband
    • Broadband is the transmission of wide bandwidth data over a high-speed internet connection. Broadband internet is a minimum of 25 Mbps download and 3 Mbps upload speeds. Broadband provides high speed internet access via multiple types of technologies including fiber optics, wireless, cable, Digital Subscriber Line(DSL) and satellite .

    • 5) USB Tethering
      • Sharing mobile data for our computers or laptops this process is called Tethering.
      • When the mobile internet connection is shared with a connected computer or laptop using physical USB data cable then it is called USB Tethering.
      • Connection Mobile to Laptop: Mobile setting-> Enable USB Tethering.

Identifying and uses of IP/MAC/IMEI of various devices


  • 1) Use of IP : An IP address is the identifier that enables your device to send or receive data packets across the internet.
    • ✬ To Identify Ip: In windows: Win + R --> cmd -->type "ipconfig"-->Press Enter

  • 2) Use of MAC: A Media Access Control address (MAC address) is required when trying to locate a device, it is assigned on device's Network Interface Card (NIC) .
    • ✬ To Identify MAC: In windows: Win + R --> cmd -->type "ipconfig/all"-->Press Enter

  • 3) Use of IMEI : It is 15 digits number, it is use to tracking of smartphones that may be stolen.
    • ✬ To Identify IMEI : *#06#



What is MAC Address?

MAC address is the physical address, which uniquely identifies each device on a given network. To make communication between two networked devices, we need two addresses: IP address and MAC address. It is assigned to the NIC (Network Interface card) of each device that can be connected to the internet. It stands for Media Access Control, and also known as Physical address, hardware address, or BIA (Burned In Address). It is globally unique; it means two devices cannot have the same MAC address. It is represented in a hexadecimal format on each device, such as 00:0a:95:9d:67:16.


Some Important Notes:

* List of letter addressing systems are:

.com : Commercial Organizations

.org : Non-Profitable Organizations

.gov : Government Departments

.net : Networking Organizations

.co : Company

.edu : Educational Institutions

.info : information


* Some country code related letter addressing system:

.in : India

.us : United States

.ca : Canada

.np : Nepal

.pk : Pakistan


What is a Browser?

A browser is a software program that is used to explore, retrieve, and display the information available on the World Wide Web. This information may be in the form of pictures, web pages, videos, and other files that all are connected via hyperlinks and categorized with the help of URLs (Uniform Resource Identifiers). For example, you are viewing this page by using a browser.


Popular Web Browsers:

  • 1) Internet Explorer: Initial release date: 16 August 1995 and Developers: Microsoft Corporation

  • 2) Microsoft Edge : Initial release date: 29 July 2015 and Developers: Microsoft Corporation

  • 3) Chrome : Initial release date: September 2, 2008 ; Developers: Google

  • 4) Mozilla Firefox : Initial release date: 23 September 2002 ; Developers: Mozilla Foundation

  • 5) Opera: Initial release date: 10 April 1995 ; Developers: Opera Software


What is surfing?

On the World Wide Web, surfing means to move from one Web page to another. When surfing, the user typically visits pages based on what interests him/her at the moment.


What is Search Engine?

A search engine is a software program that helps people find the information they are looking for online using keywords. Search engines are able to return results quickly—even with millions of websites online—by scanning the Internet continuously and indexing every page they find.


List of Search Engines are:

1 ) Bing

2) Google

3) Baidu

4) Yahoo

5) Ask.com

6) Yandex

7) Youtube

8) Lycos

9) DuckduckGo

10) Brave Search


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