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Quick Reference

File Compression

At one time or another, every computer owner has run into the problem of large files, and insufficient hard drive space. Despite thinking that you would never run out of space when you purchased your computer, you'll soon find that the applications and documents can quickly consume a hard drive. Before you know it, your computer is prompting you that disk space is running low.

One effective method to combat limited disk space is to utilize a simple compression program. The function of a compression program is to take large files and make them smaller without changing or losing any information in the file. It does this by using a complex set of algorithms and equations that reduce the size by reorganizing the bits of information in the file. When a compressed file is expanded, the bits of information are rearranged to put the file together.

Like everything in the computer world, there are many different compression application to choose from. Even though each program uses different algorithms for their compression, their compression levels are comparable. A typical compression rate for a 100k Word document containing all text is about 60%-90% of the original file size. With this in mind, choosing your own favorite compression utility is usually a matter of personal preference.

One of the most common, and user-friendly programs is called PKZIP. This program is freely available from www.PKware.com. It's user interface combines functionality with ease of use by putting the compression terminology into easily understood terms.

Another highly used compression utility is called RAR. The RAR compression format is extremely useful for packing together large programs into one very small file. It can take extremely large files and spread them out over several smaller files which can be easily transferred or stored on individual floppy disks. This program is also free to the public at www.RARsoft.com.

Another extremely popular shareware compressing agent is called ARJ, and can be found at www.ARJsoft.com. This program has all the same capabilities as RAR and PKZIP, but uses a different format and file extension.

With the various compression utilities out there, it's nice to have more than one around so that you can access other people's compressed files. You can only expand a file with a .zip extension using PKZIP. A file with the .arj extension can only be opened with ARJ, and the .rar extension can only be opened with RAR. Most files available on the Internet come compressed in one of these three above formats, and some sites offer various compression formats so you can select the one you prefer.

With files sizes ever expanding and online file transfer an important part of business today, compression allows us to save valuable disk space and time. Once you familiarize yourself with common compression formats, you can cut large files down to size in a matter of minutes.