Permissions

Our users and groups would not be that useful if they would not limit access rights. Linux comes with a basic system of discreet permissions to files and directories based on rights to read, write and execute for a given user or group. It's a simple system, but works well and is oftentimes sufficient.Alongside discreet permissions we can also take advantage of the ACL system that gives us similar building blocks, but with a bit more granuality. We'll look at the basic file and directory permissions with the file mode bits, and ownerships of files and directories to limit access to particular locations.