In such a system, the software is distributed in packages, usually encapsulated into a single file. The file, as well as the software itself, often contains information that describes the package's details, including its name, checksums, and dependencies on any other packages that it needs to work. It may also include information on how to configure the package for use and how to remove the package cleanly when it is no longer required. The package manager then uses this information to install, configure, and remove packages as requested by the user.
Some well-known examples of package management systems include: