In order to have a web site on the Internet you first need
to have a web server. Unfortunately, owning a Web server can be very costly and
requires technical expertise that most businesses don't have.
You can think of a web host as the landlord of building. A landlord
rents out storefronts to various businesses. Each business decorates and
runs their store differently, and doesn't worry about the maintenance of the
building. In a similar way a web host rents out space on a web server to
various businesses. Each business builds their own web site and never has to
worry about the maintenance of their web server.
F.A.Q. - Frequently Asked Questions about hosting.