Meaning – The term root user, refers to a user who has superuser authority. In some cases, the actual name of the account is not the determining factor; on Unix-like systems, for example, the user with a user identifier (UID) of zero is the superuser, regardless of the name of that account.
In Unix-like computer OSes (such as Linux), root is the conventional name of the user who has all rights or permissions (to all files and programs) in all modes (single- or multi-user). Alternative names include baron in BeOS and avatar on some Unix variants.
Example of usage – “It is often recommended that no-one use root as their normal user account since simple typographical errors in entering commands can cause major damage to the system. Instead, a normal user account should be used, and then either the su (substitute user) or sudo (substitute user do) command is used.”
