Known as "kiosks," these programs are already in use world wide at ATM machines, employment centers, and in health monitoring systems. Neither a mouse nor a keyboard is required. A computer user only needs to touch various boxes on a screen to control a computer. Sure, the programming behind such technology is extensive and advanced, but to the end user, it makes computer use less intimidating and plain easy. This article looks at compressed files a little closer and it describes how to compress and decompress them using two of the most popular archiving programs. Identifying Compressed Files Most files are compressed in .zip format (if you're using Windows) or .sit format (if you're using a Mac). The two most popular software programs used to compress and decompress files are Winzip and StuffIt respectively. If the program were working with a simple algebra equation like, "x + 5 = y," the variables "x" and "y" would be unknown pieces of data. Or if a program were to calculate a date "x" days from now, the variable "x" would be an unknown piece of data until we tell the program what "x" is. "1 In the past, we would be comfortable in telling new computer users not to worry about viruses and that catching a computer virus is rare. Today, that would be some of the worst advice we could give anyone. As reported in countless news reports, computer viruses are rampant and they're extremely worrisome. You may find yourself in need of more hard drive space for all those videos and mp3s that you download, for example. Or maybe that cool new programming language you've been dying to try requires more memory than what your computer currently has. Unless the activities on your computer are restricted to pure textual output (plain text files), your computer is going to get filled with a lot of "stuff" - stuff that can overfill a PC's capacity too much for the computer to function well. In other words, we can discover whether the software performs the way we want them to and should anyone try to do the same with commercial software, they'll be in for a big disappointment. Commercial software policy doesn't even allow for returns, let alone "borrowing" them to try them. The last advantage that shareware has over commercial software (but certainly not the least) is its applicability.