Q:

What is the permission group 'others' in Linux file system?

Is the group 'others' required for file permissions? Aren't 'user' and 'group' only groups try to read/write/execute file at any given moment?

A:

Others is not technically a group. Other is everyone that is not the owner or in the group. For example, if you have a file that is root:root then root is the owner, users/processes in the root group have group permissions, and you are treated as other. 

