A computer network is a bunch of computers hooked to the same system or server. This is like a bunch of TVs or radios all hooked to the same station. However, computers are really different because they don't have to broadcast the same thing to all people. Also, computers are interactive. That means that if you write to it, it will probably answer you.
Some computers stand alone and contain all of the information inside the metal cover.
Some are part of system and report to a central location for sending and receiving. But, the Internet is not really a network. It is a great big bunch of networks, all networked together. The web is a compilation of text, pictures, sound, video, and even animation. These allow you to search for a particular topic just by typing it in and clicking on search.