Definition: A compressed file is any file with the compressed attribute turned on. Most Windows computers are configured by default to display compressed files in blue text in normal file searches and in folder views.
Setting the compressed file attribute on a file will reduce the size of the file but will allow Windows to use the file just as any other. However, working with a file that is compressed will use more processor time than working with an uncompressed file because Windows has to decompress and then recompress the file during use.
Since most computers have plenty of hard drive space, compression isn't usually recommended, especially since the trade off is an overall slower computer thanks to the extra processor usage needed.
Examples:
"I tried compressing all the files on one of my hard drives but I quickly realized that it slowed my computer down so much that it wasn't worth it. I found an inexpensive hard drive at an online store and purchased it instead, adding lots of extra storage space."
