linux

XAMPP is an independent server platform, which consists mainly of the MySQL database, the Apache web server and interpreters for scripting languages: PHP and Perl. The name comes from the abbreviation of X (for any of the different operating systems), Apache, MySQL, PHP, Perl.

Ubuntu

In Ubuntu, by default, there is not really a root user, but only root access which can be gained using sudo, for instance, to update your repository list:

:~$sudo apt-get update