How to change file permissions in Linux?

Question

Debian

Hello everyone
How and is it possible to change (! Namely, change and not set the rights to create) using umask? (you need it with the help of umask)
thanks

Answer 1

You seem to be confusing something. umask is the mask for the generated files

umask is a command that determines the settings of a mask that controls how file permissions are set for newly created files

( tyts ).
To change permissions on existing files, directories, etc. - chmod.