In this era, file transfers occurred using MODEMs and transfer speeds were very limited. The ZIP file format dates to the late 1980s when it received heavy use in pre-internet-era Bulletin Board Systems, or BBSes. The ZIP file format is very popular for efficiently storing and transferring groups of files in a variety of business and personal applications. ZIP files are compressed archives that group together one or more files into a single file, compressing the files (making them smaller) that are contained inside.
