Screensavers have been around almost from the very beginning of the personal computer era in the early 1980's, and especially since the development of color monitors. You see, very early on in the development of monitor technology, it was discovered that when an image was allowed to remain on the screen unchanged for more than a few minutes, the image began to literally burn itself into the phosphor coating on the inside of the cathode ray tube, or CRT, that formed the screen. This was not only annoying, but, over time, it actually began to damage the CRT, and eventually rendered the monitor unusable. When this happened, the monitor invariably had to be replaced, as it was simply not economical to replace only the CRT.
As time went on, software developers came up with ways to work around this problem. One of the simplest ways was simply to insert a program code into the operating system which would cause the image on the screen to be altered in some way after a given length of time had passed. Since this saved the screen from what was known as "image burn-in," such a feature was naturally called a "screen-saver." Eventually, separate screen-saver programs were developed which could be added on, or "plugged in," to the operating system, providing a wide and growing variety of visual images for this important function. Such programs became even more popular as color monitors became both more popular and more sophisticated.
With the development of LED and LCD color monitors, which do not rely on an internal phosphor tube coating, the actual need for screensavers diminished to some extent. However, there is still a surprising number and variety of screensavers available for computer owners to use with their monitors. Many PC owners, myself included, actually enjoy watching the screensavers when they are in operation. Many screensavers, in fact, now offer 3D graphics, animation, sound effects, and even music among their features, all of which can, at least to some extent, be set or controlled by the user to suit their needs or preferences.
Just recently, I added several screensavers to the more than 1 dozen I already have on my system. I now have at my disposal a wide variety of nature-related scenes, such as gardens, waterfalls, and even an awe-inspiring picture of a tornado! Most of these include animation, sound effects (even bird calls and quacking ducks!), and music! I can switch from one to another simply by using a drop-down menu in the "Control Panel" section of Windows XP Home Edition. (I should also mention that similar technology is available for background screens, also known as "wallpapers.") This allows me to vary the images that show up on my screen, depending on the season of the year, or simply my own mood! Being able to watch such imagery on my computer screen when I take a break from writing or other PC-related tasks is soothing to the spirit, to say the least!
By now, you're probably asking, "OK, smart guy, who pays for this stuff, and how?" The simple answer is that they are advertiser-supported. When the initial screensaver is downloaded, the user is asked to choose one or more services to subscribe to, which then occasionally send emails or display an advertisement prior to the screensaver's activation. I have found, however, that in most cases, such ads can be declined or bypassed in some way. I do, however, recommend that the new user subscribe to the screensaver developer's own newsletter, as new screensavers are made available from time to time, which the user may wish to add to their collection.
One caveat: This kind of software involves extremely sophisticated graphics, especially if 3D images are generated. It therefore makes significant demands on both the graphics card and the CPU. In many systems, this may cause the system to generate more heat than you might realize. That being the case, the use of fan-control software, such as SpeedFan, is strongly recommended. You may also wish to consider upgrading your PC's cooling capacity.
For more information on animated screensavers, go to www.freeze.com, or search on the phrase, "animated screensavers," with your preferred search engine.