A computer network is a series of two or more computers connected to each other. Generally, there are two types of networks, home networks and office networks. Both types provide many of the same benefits.
Computer networks allow file sharing. If you have three computers at home and all three users want access to an mp3 collection. Without a network, you'd have to either upload the collection to the Internet or put it onto some form of removable storage to transfer individually to each other computer. On a network, you can simply make the collection "public" so that any network user can access it, even though it's still only on your computer. On an office network, files can be made public, providing easy access for multiple employees.
Perhaps your coveted mp3 collection is full of music protected by copyright; if so, you can easily set shared network files to where they cannot be copied but only used. This would mean that, while others on the network can enjoy the music they cannot copy it over to their machine. Also, individual directories can be assigned a password so that authorized users are allowed. This feature is great for offices, as you can store all business files on one network and not have to worry about employees having access to sensitive information over the network.
Resources and Cost
Networks also allow computers to share certain resources, such as printers and modems. Instead of buying a printer for each computer, you can simply buy one and connect it to the network. Also, some software manufacturers release special network versions of their software designed to run on many computers through a network instead of buying an individual use license for each computer.
Wireless networking offers all the benefits of a traditional network are achieved without physically connecting the computers to each other or a central server. While they're still all connected, it is done with wireless technology, allowing for more mobility and convenience.