Linux is an inherently secure operating system. Every part of the operating system has been configured to be secure by default. Every file is owned by a particular user, and that user is able to allocate permissions to that file in order to restrict other users and groups from accessing the file.

By default, all commands that are run in bash are run as the current user. The current user is normally the Pi user. This user is a standard user, and this means that you will not be able to run any commands that can affect other users, such as installing software or changing the network configuration of your Raspberry Pi.

Fortunately, it is easy to run commands as the root or superuser. This user has unlimited access to every part of the operating system and must be used with caution.

To run a command as the superuser, you can use use the sudo utility. The sudo utility lets you run a command as a different user from what you are logged in as.

In order to use the sudo utility...