Okay, so in our discussion of the ls -l option, we promised to explain what we meant by permissions, owner and group. Well here we go...
Permissions are a basic part of the UNIX security system. In short, they define who gets to do what with which files.
Specifically, permissions define who gets to:
Your access privileges are defined in the password and group files. Before we get into the nitty gritty of permissions, let's take a look at these files.