On Unix systems, a home directory is a path on the local file system where a user's personal files are stored. Typically this includes configuration files (usually hidden, i.e. starting with a "."), documents, locally installed programs etc. The home directory is defined in the file /etc/passwd as part of a user's login information. On most Linux systems, the home directory takes the form /home/<username>.

Separating user data from system-wide data avoids redundancy and makes backups of important files relatively simple. On the other hand, Trojan horses, viruseses and wormss running under the user's name and with their privileges will in most cases only be able to alter the files in the user's home directory, and perhaps some files belonging to workgroups the user is a part of, but not actual system files.