So far, we have seen how we can manipulate the (basic) permissions for files and directories. However, we haven't dealt with changing either the owner or the group for a file. It would be a little impractical to always have to work with users and groups as they were at creation time. For Linux, we can use two tools to change the owner and group: change owner (chown) and change group (chgrp). However, there is one very important thing to note: these commands can only be executed for someone with root permissions (which will, typically, be the root user). So, before we introduce you to chown and chgrp, let's look at sudo!