WordPress has a built-in system for managing site menus.
On the admin area of the site, there is a section dedicated to all of the menus created on your site.
You are able to create (navigation) menus and have them display on the front-end via hard-coding or widget use.
One of the great things about WordPress is the ability for site owners to manage their own menus without the need for developers to get involved.
The editor has a drag-and-drop function, making it easy to add new links in or rearrange the existing ones.