Shared hosting, also sometimes referred to as virtual hosting, is a web hosting environment where multiple individual hosting accounts are stored on a single web server. Think of a web server as a very powerful computer loaded with resources. Each of the accounts on the server shares the server's system resources. These resources include disk space, data transfer and server processing power.
Shared Hosting offers you an affordable solution to get your web site up and running because all the related server hosting costs are shared and spread out among the other users/accounts who are being hosted on that server.