avatarIgor Jovanovic M.Sc.

Summary

This article provides an introduction to computer networking, explaining how computers are connected via cables and the role of electrical signals in transmitting binary code, which represents data such as chat messages, PDFs, music, and photos.

Abstract

The article begins by defining a network as a group or system of interconnected people or things, then applies this concept to computer networks, which are simply a bunch of computers connected with each other. The author emphasizes that there is no magic involved, just cables. The article then explains how the internet is a network of interconnected computers, and how it is possible to physically track the cable from one computer to another, even across continents. The author provides links to images of underwater cables that carry internet traffic between continents. The article also covers local networks, which are smaller networks used for connecting devices to a computer via cable or WiFi. The author explains the process of sending a photo from one computer to another, illustrating the path that the binary representation of the photo takes through various cables and networks. The article concludes by mentioning that the next post will cover IP addressing and provides a link to a more detailed guide on computer networks.

Bullet points

  • A network is a group or system of interconnected people or things.
  • Computer networks are a bunch of computers connected with each other via cables.
  • The internet is a network of interconnected computers that can be physically tracked via cables.
  • Underwater cables carry internet traffic between continents.
  • Local networks are smaller networks used for connecting devices to a computer via cable or WiFi.
  • The binary representation of data is transmitted via electrical signals through cables.
  • The next post will cover IP addressing.
  • A link to a more detailed guide on computer networks is provided.

Introduction To Computer Networking (For a Killer Engineering Career)

Most probably the most valuable lesson if you are looking to start in engineering or level up your engineering skills.

Want to learn computer networks basics? Made at Canva.com

This article is great to cover the gaps (if you are already a senior) or to start confidently if you are at the beginning of an IT career path (or changing to IT).

The knowledge of computer network fundamentals can help you climb to the (more) senior position levels rather fast since most IT professionals actually miss this part (more or less). (So, you will have the knowledge others do not have if you make it to the end of my engineering posts series.)

Also, IT job interviews always require some knowledge of computer networks. It doesn’t matter if you are applying for a programming position or operations related, the networks are always there! By the end of the post, these questions will be a piece of cake for you!

Now, let’s warm up with the definition of a network (not a computer network still!) provided by Oxford Languages.

A network is a group or system of interconnected people or things.

… and now let’s get this to the level of computer networks which brings us to the first concept.

Introduction To Computer Networking

Similar to the general definition of a network, computer networks are nothing more than a bunch of computers connected with each other (see, that was easy).

The word to watch for is “connected”, so what is connecting these computers? The answer is cables!

There are several different technical components that are involved here, but at this point, it is important to understand that there is no MAGIC, it’s all cables!

The internet network

So if you are “connected to the internet” (the internet being a bunch of interconnected computers), you can physically track cable from your modem to another’s computer modem that might be on another end of the world — (if you don’t have anything smarter to do).

Here is a picture of these cables at the ocean bottom [Click here].

…and there is a picture of all the underwater cables that exist across the continents [Click to see].

These cables, therefore, serve the purpose of transmitting electrical signals issued by one computer to another/other computer(s) in the network. The electrical signals hold the binary code that reflects, say a chat message (PDFs, music, photos, … also). In more technical terms, the content travels via MESSAGEs that get broken up and organized into smaller units called PACKETS (I wrote another post to explain these in detail).

Once the binary code reaches the end computer (via the network), that computer’s hardware understands the binary code and translates it for you to the human-readable format (that’s how you can watch funny cat videos on YouTube when you are bored).

Local networks

As opposed to WWW (world wide web, a.k.a. the internet) there are also much smaller computer networks that you are using every day (non-public networks).

These are devices that connect to your computer via cable (and router) for instance. If you ever played Counter Strike 1.6 with your friends in a LAN (local area network ), you have a very good idea of what these smaller-scale networks look like (also if you ever printed something).

Local Area Network cable (LAN) — Photo by Markus Spiske on Unsplash

Now when we know — cables, cables, and cables! — we can understand the networking fundamentals on a high level.

Here is the full path of travel via the internet network: you take a photo of your cat (with the desire to send it to a friend on another continent) and click that send button. The binary representation of that photo reaches your modem via cable or WIFI (WiFi uses radio signals). Then this signal travels over the cables from the walls that are installed by your internet provider (e.g., T-Mobile, Ziggo) and further through the cables installed in the ground of your city (if you don’t know what are local internet providers just wait for the first YouTube ads since they are bombarding with these!! ).

By traveling, this signal is moving through the cables OWNED by different companies (internet providers) or government-related authorities of different sizes since most of those under-sea projects are huge infrastructural investments done by conglomerates and different countries.

Click here to see the underground cables photo.

Once the signal has traveled the undergrounds, the seas, and the oceans it has finally arrived at the destination country and now has been taken by the local internet provider cables and ultimately reaches the walls of the receiver (your friend) and her modem and computer.

And here is that cat photo I am sending you via the same logic!

Source: Giphy

Now that we understand the high-level infrastructure, we can go a level deeper and better understand the second important concept which is IP addressing (in the next post — make sure you follow me).

Also, you can visit my ultimate guide on computer networks here to continue learning right away.

P.S. Write a comment if you need any part of the introduction to the computer networking section clarified.

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