During your travels, you may encounter files with extensions such as .ZIP, .ARJ, .HQX, .gz, etc. These are files that contain one or more files in a compressed format. Much like brands of Cola, there are different types of compression formats, each offering faster or smaller compression routines. The basic theory behind file compression is, imagine a text file with "0000011100000" in it, nothing more. That’s 13 characters. If we look at it like so: "053105" (5 0’s, 3-1’s, 5 0’s) it’s only 6 characters long now. This is a very crude example, but using advanced mathematical algorithms, a text file can be compressed to an average of 75% of its original size. That means a 1 hour file transfer is now 10-15 minutes.

To do this conversion, utilities such as PKZip were created to compress files as small and as quickly as possible. The ZIP format is about the most widely used. The PKZip utilities allow you to create and extract compressed files. For example, say you had 10 documents to email to someone. Rather than send 10 messages with 10 file attachments, you could use PKZip to compress all 10 documents into one file. You are not only saving in messages, you’re also shortening the transmission process by compressing them. The recipient of the resulting ZIP file would also have to have the PKZip utilities to decompress it.

If you need a file extraction program, one of the best for Windows is a program called WinZip. You can find it on our home page, on our FTP site and on an infinite number of sites around the Internet. Typically a ZIP file contains multiple files and/or directories. It’s usually best to extract a ZIP file to a temporary directory first, so that you don’t leave a lot of unwanted files behind.

If there is a specific compression utility you need, try a web search using the name of the utility (Gzip, ARJ, etc.). Most shareware sites carry copies of almost any compression utility you might need.