In Linux the file permissions determine who can access a file/directory, and what actions they can perform on it

The three main types of permissions are:Read(r),write(w) and execute(x).

Every file/directory in Linux has three sets of permissions: one for the owner, one for the group, and one for everyone else.

Read permission (r) allows a user to view the contents of a file or directory

Write permission (w) allows a user to modify the contents of a file or create/delete/rename files in a directory

Execute permission (x) allows a user to run a file /directory.

Permissions can be set using either symbolic notation (u+rwx) or numeric notation (775)

The chmod command is used to change file permissions in Linux

The chown command is used to change the owner of a file or directory.