Root / regular Linux user
In Linux there is a “root” user (which is the administrator) and there are regular “users” (often called “user”). Linux users should always log in as a regular user, and type “su -” or “sudo” to obtain root permissions only on an as-required-basis. Keeping root permissions, or indeed logging in as root user as a routine matter, creates a major security risk for the beginner (if their PC is connected to the Internet). It also creates a significant operating risk, in that it is relatively easy for experts and newbies alike, to trash their system when operating with root permissions.
Some super user definitions are: