GNU/Linux is a
multiuser system which means more than one user can access your
machine, each with the ability to keep his own data and
configuration files private and protected from other users. The
different user accounts must be created by the administrator whom
is called root
. You must have set his password during the
installation, and he has no restrictions at
all on the system.
It's very important to understand the terms “to log in” and “to log out”. To log in means to identify yourself to the computer. Think of it as a security officer verifying who you are before letting you in. After logging in, the system takes a number of actions in order to give you access to the system's resources. By logging in, you start a so-called “session”.
When you log out you are telling the system you no longer need to use its resources. Your personal session is closed, you exit the graphical interface and the login screen appears once more.