What is this technique called?

In the Install Plugins admin panel, clicking Install on a selected plugin pops up what looks like a modal dialog on top of the admin panel, with some actions for the selected plugin.
What is this technique called?
I want to look for more generalized examples of it, but I can’t think of a search term for it.
I assume it exploits AJAX, but that term is far to broad.

Wouldn’t that be a great way to force a login? But I can’t find a plugin that uses this particular technique.