The Menu module displays a menu on your site front-end - which is what your site visitors see.
Menus can be displayed in a wide variety of ways by using the menu options and css menu styles.
The Menu Module will display a menu of your choice - but the menu you want to choose will have had to be set up previously using your Menu Manager.
Your Menu Module is an effective way of creating multiple menus on your website.
In Joomla version 3.10.x Modules are created and managed via the administrator area menu 'Extensions' tab.