Computer networks are all around us today, and they make up a large portion of the infrastructure which carries every form of communication or entertainment on our planet. But, what are computer networks, and what is it that they do?
To understand what a network is, it helps to understand the word itself, network.
Thankfully, this word can be separated into two others which might already be easily recognized: net and work. Considering the first portion, net, we can imagine any kind of net we might be familiar with: a fishing net, a hair net, a bug net, etc. These nets are all pretty much the same. They are made up of long strands of thread or other materials which cross over each other and come together to form a larger shape, a net.
A computer network is very similar in structure to these other kinds of nets, except the strands are miles and miles of copper wires, fiber-optic cables, or even wireless radio signals. The points at which each thread “crosses over” another would be where our computer terminals, routers, cellular phones, satellites, or any other device would be connected. These devices on the net are constantly communicating with or about each other over the strands, and it is this function the computer net, the communication, which brings us to the second portion of our word: work.
The work done in the case of a computer network is communication, and there is A LOT of it.
Every device connected to the network is constantly sending and receiving information. This information includes user-generated things like files, login requests, or emails; however, most of the communication sent between devices is not just by or between human users, but between the devices themselves.
This kind of communication on a network is mostly invisible to the every-day web browser or streaming video user; but, in fact, it is the most vital data which exists on the network, helping to keep the network alive and in working order. This hidden communication includes things such as the shape of the net, the position of each device, and the rules of operating on the network.
If the network were a city, this unseen communication would be like the map, complete with device addresses, road positions, and even speed limit signs.
Devices constantly send this information back and forth to ensure they are connected to the network and that they know the proper way to transmit data. This means when a computer, television, or phone is not being used it is still transmitting and receiving on the network. Sometimes, even when devices are powered “off” or in “sleep” mode, they still communicate over the network to ensure their address on the map is held and they know the rules of how to connect and transmit.
Simply put, if your device is connected to a network, it is most always active.
We rely on computer networks for much of our communication, entertainment, and even a lot of our shopping in the world today. A network can be understood best by breaking down the word itself, net- work. Each device connects over long “strands” of cable, wire, or wireless signal to form a larger shape (a net) which performs constant communication (work). That communication is often generated by users, but most of the actual work on the network is merely between the devices themselves, invisible and unknown to average users.
Networks can transmit music or movies, connect phone calls, update bank information, and even help control the temperature in your home. Yet, most of the communication which happens on a computer network is not part of these tasks. Devices which exist on networks constantly communicate with each other and share information. This communication only stops if there is a problem with a device or the connecting strands of the net itself. Even sleep mode or turning off a device often does not stop the communication from devices that are network connected.
So, even when everyone in your neighborhood is fast asleep, their phones, televisions, computers, and tablets are all wide awake, working hard and chatting away over the strands that link them together into a larger net-like shape.
Learn More
Introducing Basic Network Concepts
https://www3.nd.edu/~cpoellab/teaching/cse40814_fall14/networks.pdf
What is a Network?
http://pluto.ksi.edu/~cyh/cis370/ebook/ch01b.htm
Computer Networks
http://ca.pbslearningmedia.org/resource/ate10.sci.engin.design.networks/computer-networks/
