Screensavers were originally designed to protect computer monitors from phosphor burn-in. Early CRT monitors, particularly monochrome ones, had problems with the same image being displayed for a long time. The phosphors, used to make the pixels in the display, would glow at a constant rate for such a long period of time that they would actually discolor the glass surface of the CRT. This discoloration would then be visible as a faint image overlaying whatever else was displayed on the monitor. Advances in display technology and the advent of energy-saver monitors have virtually eliminated the need for screensavers. But we still use them.
Here are the main reasons why:
- Entertainment - The most common reason we use screensavers is for the fun of it. Watching that macaroni dance across the screen to the tune of "Hey Macarena" can be a great diversion for a few minutes.
- Security - By setting up a screensaver with password protection, you can walk away from your computer and feel comfortable that nobody is going to be able to see any sensitive information.
- Uniform look - Many companies require all employees to use a particular screensaver. This creates a uniform and perhaps aesthetic environment and ensures that no inappropriate screensavers are displayed.
- Advertisement - Companies, particularly retail businesses, that have computers in areas accessible to customers will often have a screensaver that promotes their business or product.
- Information - A lot of screensavers provide either static or real-time information. A screensaver may cycle through a series of trivia questions. Another may pull stock information from a Web site and stream it across the screen.
- Distributed computing - Another form of screensaver takes advantage of your computer's inactivity to process data from another source. A good example of this type of screensaver is SETI@Home, which is currently utilized by thousands of computer users. This screensaver displays a graph of the radio spectrum and processes radio-signal information received from the SETI (Search for Extraterrestrial Intelligence) servers. It sends back results based on the data processed. By using the combined processing power of all of these computers, SETI is significantly reducing the amount of time it takes to sift through all the signals received from its radio telescopes.