I just need a name!

Is there a name for this page functionality?

Basically its when one page has a side menu which, when clicked, rather than taking you to a new URL just brings up difffernt content by showing and hiding. Its often used on customer service pages like the one in the link:

https://www.sandrolopez.com/uploads/2017/03/Screenshot-2017-03-30-12.16.38.png

I know how to build this manually but I’m trying to find the method which would be most simple for a client to update, probably a plugin.

I dont think it needs to load with ajax or anything as it just needs to hide and show basic text.