Group management
Now that we know how to make new user accounts, manage existing user accounts, and switch between user accounts, we need to learn how to manage groups. Linux’s implementation of the concept of groups is not all that dissimilar to that of other operating systems, and it essentially performs the same function. Controlling a user’s access to the resources on your server can be done more effectively with the help of groups. You can grant access to users or deny access to users by simply adding them to or removing them from a group that has been assigned to a resource (such as a file or directory). This is made possible by assigning a group to the resource in question. The way that this is handled in Linux is such that each and every file and directory has both a user and a group that claims ownership of it. When using Linux, ownership is assigned on a one-to-one basis, meaning that each file or directory has just one user and just one group associated with...