April 15, 2023
A computer network is a system that makes it possible for 2 or more devices, such as mobile phone, smart devices, computers, servers, and so on, to connect. Once a device is connected to at least one other device, the connected devices can transmit and share data.
How devices connect in a network
Devices in a computer network can be connected physically (wired) via an ethernet cable or over Wi-Fi (wireless).
In the image above we see a an example of a very simple home network. There's a few wired devices that connect to a router via a switch (I'll cover the roles of switches and routers in an upcoming post) as well as a couple of wireless devices that connect directly to the router. How a home network is set up will vary from one house to the next but this gives us a good high-level overview of how devices in our own home might 'talk' to each other.
Now obviously, networks extend beyond the home. At the time of writing this there are 10 billion devices connected to the Internet, all of which need to be able to communicate with each other so simple networks like the one above, just aren't going to cut it. Let's take a look at the different types of networks can, categorised by their scopes (the area they cover):
- Personal area network (PAN): A PAN is a very small network that may only connect as few as 2 devices. For instance, you may have a gaming system with a wireless controller that connects to the console via bluetooth. That connection between your controller and your gaming console constitutes a PAN.
- Local area network (LAN): A LAN is usually local to a building, or maybe just an area within that building. It is what you would find in your home or perhaps in a work setting. This type of network allows, for example, computers within a department to share resources such as the photocopier or allow those computers to access the same set of files that might be stored on a computer acting as a file server.
- Campus area network (CAN): This type of network is typically found in university or business campuses and makes it possible to interconnect nearby buildings, each of which can have a LAN within the building.
- Metropolitan area network (MAN): A MAN is the type of network that would be used by any business that have multiple locations spread across a large metropolitan area. Offices can connect to a MAN and then they can all communicate between one another at a very high speed.
- Wide area network (WAN): The furthest reaching of all the networks, WANs interconnect networks over large geographical regions. This is suitable for large companies that have offices scattered around the country/globe.
As you can see, networks come if varying sizes to cater to many different needs.