zip is a compression and file packaging utility, which is analogous to a combination of the UNIX commands tar and compress and is compatible with PKZIP, the ZIP for MSDOS systems. The zip utility is useful for packaging a set of files for distribution; for archiving files and for saving disk space by temporarily compressing unused files or directories.

zip puts one or more compressed files into a single zip archive along with information about the files (name, path, date, time of last modification, protection, and check information to verify file integrity). An entire directory structure can be packed into a zip archive with a single command.

zip has one compression method (deflation) and can also store files without compression. It automatically chooses the better of the two for each file. Compression ratios 2:1 to 3:1 are common for text files. Unzip will list, test or extract files from a zip archive. By default it extracts all files from the specified zip file into the current directory and subdirectories below it.