When using Linux we have many ways to manage access to resources: the most basic one is by setting the appropriate UGO/RWX permissions on files and directories. In some occasions we may also want to make use of the setuid, the setgid and the sticky bit. Furthermore, we can use ACLs (Access Control List) in order to achieve an higher level of granularity or implement Mandatory Access Control security such those based SELinux or AppArmor.
In addition to the strategies mentioned above, on most filesystems we can manipulate a set of “attributes” in order, for example, to make a file immutable.
