Compressing files has only one main purpose – to make them smaller. However, it also has several other sub-uses. Compression programs were mainly used to reclaim disk space as unused or infrequently used files could be made smaller and thus freeing up some space on the hard drive. This practice was also extended to whole hard drives using programs like “Stacker” and “Doubledrive” back in the days of MS-DOS to compress all files while remaining accessible by the OS for immediate use. However with larger hard drives becoming cheaper every day, these reasons have now disappeared.
Compression programs are now mainly used to send files across the internet. This gives a user a few distinct advantages.
1. Several files can be “bunched” together and sent as 1 file. As such the total size to be uploaded by the user and downloaded by the recipient becomes less. However not all files can be compressed enough to be of any practical use. Video files and JPG’s have already had compression algorithms run on them so the compression program you use will have little or no effect on them
2. The files can be password protected and encrypted as well. This gives a great deal of security to the data being transmitted and anyone intercepting the data will find it almost impossible to decrypt it.
3. The integrity of the data can be judged immediately upon receipt of the file. The compressed file simply will not “open” if it was not transmitted properly. Although this does mean that the file will have to be re-sent, it saves the recipient the frustration of receiving several corrupted files.