Screen Savers are something that you can install it on your computer that will display on your computer screen when your computer is sleeping.

Screen savers are popular things to give away on sites.

Advertisers put them on their sites so that people will install them on their computers and see something that reminds them of the product every time their computer goes to sleep. And then when other people see your screen saver, and they like it, they will ask you where you got it. When you tell them, they might go to that site and see something they like other than the screen saver and then they might buy something or give their e-mail. It is a good way of sucking people into their site.