VIDEO : How Does 'The Nun' Fit In To 'The Conjuring' Universe

A new horror film,The Nun, is set to scare audiences this weekend.
Comicbook.com says the film ties into the Conjuring horror film universe.
How does the film fit into the Conjuring universe?
The Nun is a prequel set at a Romanian monastery in 1952.
Demon Valak is the main antagonist of the film, building on its original appearance in The Conjuring 2.