A File Compression/Decompression process. To decompress a file that was reduced in size by using an algorhythmic technique to remove redundant, recreatable information.

A proprietary term for the programs Winzip or the old school pkzip.

Take the zipper hook thingy (it probably has a name that I'm too feeble to remember), and move it downward, thereby opening the zipper and freeing whatever it contains.
Must be done if you're wearing zippered clothing and need to shit, piss, fuck, change outfits, or expose yourself for no good reason.