Can you explain briefly the main concepts and command line tools used to manage file permissions? Solution Each file has rights for three different categories: the owner of the file, the group associated with the file, and everybody else. Rights mean the right to read the file, the right to write to the file, or the right to execute the file in case of a script or program. On the CLI, you may change the owner with chown, e.g. chown guillermooo change the group with chgrp, e.g. chgrp root change the rights with chmod, e.g. chmod u+w filename.ext (Adds writing permission for the owner of the file filename.ext) If you\'d like to know more about each of these tools, open a terminal and type man [tool], e.g. man chmod..