How to set up and manage WordPress Multisite

WordPress Multisite (or WordPress MultiUser/WPMU) is a WordPress feature that allows you to run multiple WordPress sites from within one WordPress installation. All these installations make up a so-called ‘network’. All the sites in this network share one database, however,  they have separate tables within this database and different directories for media uploads. Also, these sites share the same plugins and themes.

Source: How to set up and manage WordPress Multisite (WPMU) (cPanel: