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Someone asked me to send them something as a zipped file recently, but I did not know what it meant. Can you help? - Senan, Co Carlow, via e-mail

Zipping is a way of compressing files to make them easier and quicker to send over the Internet. It works by making the files take up less memory. The amount that a file's load can be reduced by varies greatly though. Some files can be reduced by as much as 85 per cent, but others by as little as five or 10 per cent.

As a general rule, movie files such as MPEG, picture files such as JPEG and music files such as MP3 will not be reduced by much through zipping as they are compressed files anyway. However, files with text and graphics, which you may be using for overhead projection for instance, can be greatly reduced in size by being zipped if they have not previously been compressed.

Zipping can be of great benefit if you need to have something available to you outside your office or home. By using "zipping" and "unzipping" software tools such as Winzip (for PCs) and ZipIt (for Macs), you can email a file to an Internet-based e-mail address and then download it at another location. However, before doing this, make sure that the computer at the other end is compatible with what you are doing (something I failed to do recently).

If zipping a file is not an option for whatever reason, using a zip drive and zip disk is something worth considering. A zip disk looks like a fatter version of the 3.5-inch floppy disk and works in the same way. The benefit of a zip disk though, is that it can hold up to 250 Mb of information, which is enormous compared to the 1.4 Mb capacity of most floppies. Some computer come with a zip drive; with others they have to be attached.

The volume they can hold makes zip disks a very good back up system for vital files. It also makes it easier to transfer files from one computer to another. As with floppies, you can delete and re-record with zips. The one drawback is the cost. Buying in bulk is recommended.