There are several types of networks. For this post, I’ll be focusing on the type used at my job: a LAN. LAN stands for local area network. It links computers that are close together geographically, e.g., in the same building. I only understood what networks actually do when I was trying to transfer files from one computer to another. I had had a vague idea that a network had something to do with connecting the computer to the internet (completely incorrect, I realize now). I was clicking around, trying to find how to email the files to myself so I could download them onto the other computer when I clicked on “Network”. (and yes I know I could have opened a browser, gone to my email, opened a new one, and attached the files, but see how long and boring a sentence that is? Doing it in real life is even worse) After clicking on “Network”, I was surprised to find a list of the other computers in the office.
It was a moment of beautiful epiphany. The world opened around me like a flower in bloom and I understood networks at last.
That may be a slight exaggeration, but I do know what networks are now, so I think that’s a big step forward. To go into greater depth on LANs, networks allow computers to communicate and share information over either ethernet, which is what my work uses, or through a connection built into the computer. Macs, for instance, can connect to each other over Appletalk, which is built into each computer and requires no cables. Ethernet, however, does require cables. At my job, each computer either transmits signals to a box or is connected to the ethernet router. The box is the wireless access point which lets computers that cannot be easily connected to the actual router still have access to the network. And it’s not just computers that can connect to the network. Printers, fax machines, etc. can be connected so the whole office can share them. This can cause problems if people are transmitting at the same time, but protocols within the ethernet can deal with that by retrying to transmit at random intervals to avoid that same collision.