Networking With SAPT-0x01: Introduction to Computer Network

Prajit Sindhkar
5 min readOct 14, 2021


Hello guys👋👋 ,Prajit here from the BUG XS Team . I am going to start a new write-up series, “Networking With SAPT”, which will help all those who want to learn networking, and I will start from complete basics, so anyone who doesn’t know a thing about computer networks, can start learning from here✌️.This series will go chapter-wise to give proper order to the learning process. That being said, let’s start our chapter 0x01: Introduction to Computer Network.

What is Computer Network?

Computer Network refers to a system of connected computing devices (such as laptops, desktops, servers, smartphones, and tablets) and an ever-expanding array of IoT devices (such as cameras, door locks, doorbells, refrigerators, audio/visual systems, thermostats, and various sensors) which are connected to each other to share resources and information.

Advantages of Computer Network:

  1. File Sharing: Files can be stored on a central node (the file server) that can be shared and made available to each and every user in an organization. And the greatest advantage of this is you don’t require to have physical connection (wire, USB, etc) for this.
  2. Flexible Access: This innovation is known to be truly adaptable. For networks, flexibility would refer to the ability to adapt the available network resources, such as flows or topology, to changes of design requirements, e.g., shorter latency budgets or different traffic distributions.
  3. Entertainment: The streaming of media like video, audio, etc is all possible due to computer networks.
  4. Reliable: Reliability implies backing up information. In case equipment crashes, and the information gets undermined or inaccessible on one PC, another duplicate of similar information is accessible on another workstation for future use, which prompts smooth working and further handling without interruption.
  5. Faster Problem Solving: Big procedure of networking process is distributed in small parts(we will see this in future), so in case of any error, it is easier to pin-point exactly where the error lies.

Disadvantages of Computer Network:

  1. Cost: Building a network can be costly as cables and devices are expensive.
  2. Transmission of Malware: If one of the PC on a network system gets contaminated with an infection, there is a possibility for alternate frameworks to get infected as well.
  3. Lacks Robustness: If a network’s principle server separates, the whole framework would end up futile. Similarly, if it has a bridging device or a central linking server that fails, the entire network would also come to a standstill.
  4. Lacks Independence: PC will be subject to the primary document server, which implies that, in the event that it separates, the framework would end up futile, making clients inactive. Hence PC can’t work independently.

Types of Computer Network:

Computer Networks can be categorized based on their size as well as their purpose. Here “size” of the network is expressed by geographic area.

There are mainly 3 types of computer network:

Main Types of Computer Network
  1. Local Area Network(LAN): A local area network is a computer network the interconnects computers within a limited area such as a residence, school, laboratory, university campus or office buildings.
  2. Metropolitan Area Network(MAN): A metropolitan area network is a computer network that interconnects with computer in a metropolitan area like city. This can also be used for interconnection of different LAN. MAN is larger than LAN but smaller than WAN, in terms of area covered.
  3. Wide Area Network(WAN): A wide area network is a computer network that exists over a large-scale geographical area. A WAN connects different networks including MAN & LAN.
Working of different types of network together
Difference between LAN, MAN & WAN

Now, apart from these main 3 types of computer network, there are some more types, let us discuss them one by one.

4. Personal Area Network(PAN): This is the smallest and most basic network that you’ll find. It’s meant to cover a very small area (typically a single room or building). The most well-known PAN technology is Bluetooth connection. A PAN is most commonly used for one individual and to connect just a handful of devices such as a computer, smart phone, and printer.

5. Wireless Local Area Network(WLAN): A WLAN is simply a LAN that does not rely on cables to connect to the network. So, when you’re using WiFi, you’re using a WLAN. WLANs are typically used in the same scenario as LANs, it just depends on whether you’d prefer wires or wireless.

6. Storage Area Network(SAN): A SAN is another type of LAN that’s designed to handle large data transfers and storage. This purpose of this network is to move larger, more complex storage resources away from the network into a separate, high-performance atmosphere. Doing this not only allows for easy retrieval and storage of the data but it also frees up space and improves overall performance of the original network.

7. Virtual Private Network(VPN): The point of a VPN is to increase security and privacy while accessing a network. The VPN acts as a middleman between you and the network by encrypting your data and hiding your identity. This is mostly used by hacker to cover their traces. One more thing you should know is TOR. It is, short for “The Onion Router,” is an open source privacy network that permits users to browse the web anonymously. Tor was initially developed and solely used by the U.S. Navy to protect sensitive government communications before the network was made available to the public.

There are also some differences between TOR and VPN, even though both are used for specifically same purpose.

Difference between Tor and VPN

Now this is all about this chapter, hope you liked it, if you found this informative, do not forget to clap👏 and do let me know if you have any doubts✌️. Also since this is my first write-up of the series there might be some mistakes or some things in which I could improve the further write-ups, so feel free to give suggestions on write-up or how the flow of content is showing. I am aiming to write one each week, and if possible I would write more in a week. Do follow for future chapters updates.😁

Thanks For Reading 😊

Profile Links:




BUG XS Official Website:


Difference between Tor and VPN — GeeksforGeeks

Advantages and Disadvantages of Computer Networking — GeeksforGeeks

7 Types of Computer Networks | IT Blog | Pittsburgh, PA | Sierra Experts

3150710_CN_GTU_Study_Material_Presentations_Unit-1_13082021073347PM.pptx (



Prajit Sindhkar

I am a India Based Security Researcher, Bugcrowd Top 500 Hacker and Bug Bounty Leader of the BUGXS Community