Answer:
A network, in the broadest sense, is a path or paths of interconnections between sources of information or data. Networks exist to move information around, often times across the world, sometimes at the speed of light.
One example of a biological network is your nervous system; your brain uses this neural net to communicate with and control the rest of your body.
A computer network consists of (you guessed it) computers joined together to allow trading of data. Modern networks are the reason the Internet exists. Websites like Facebook, Twitter and Myspace (social networking) all rely on the secure transmission of data for users to interact with each other. The Internet is also the most massive advertising platform ever. Through it, companies have the potential to reach everyone in the modern world. Over 200 million people have access to the net.