Which command is used to add a user in a Linux system?

The command used to add a user in a Linux system is 'useradd.' This command is a standard utility that is included with many Linux distributions and directly interacts with the system's user database. When executed, it creates a new user account and sets up the necessary files and settings needed for that account.

It is important to note that 'useradd' provides a more granular level of control compared to some other commands. It allows administrators to specify various parameters, such as the user's home directory, shell, and user ID. Additionally, 'useradd' typically requires superuser (root) privileges, ensuring that effectively managing user accounts is a task reserved for authorized personnel.

Other options do not correspond to valid commands used for adding users in Linux systems. For instance, 'adduser' might be available in some distributions as a more user-friendly wrapper around 'useradd,' but it is not universally standard and might behave differently depending on the system. Commands like 'createuser' and 'newuser' do not exist in standard Linux distributions, which is why they are not suitable choices for adding a user.