Screen Savers have been used since the early days of PC operating systems. Screensavers were originally made because the CRT monitors would burn the desktop background into the screen producing a ghost effect which remained on the screen permanently. A screensaver which typically utilizes images that change in a random order with various animated effects prevents this ghosting issue. Today LCD and other types of monitors are more common, which are not as susceptible to monitor burning. However, the screen saver lives on which provides nature lovers a way to display their favorite nature screen saver when their desktop or laptop is idle. You may choose to pay for a nature screensaver and often paying for a screen saver will provide more options, best images and the most features.
If you do not have the extra money to pay $5, $10 or $20 for a nature screensaver (personally I would never pay more than $20 for any screensaver) then there are many free nature screensavers available at download websites. It is important however, that you make certain you download your nature screensaver from a reputable website and that you read the terms and obligations of installing ANY screensaver. Often unscrupulous software designers will install adware or spyware on your PC. Unfortunately, practices like this are disclosed in the terms of a screensaver software install in legal mumbo jumbo which most people overlook.