Hi-Rez Studios released a new video for Paladins: Champions of the Realm today that covers the Haven item and its use during matches.
Haven is a more traditional item that is bought in many Paladins matches. It gives players a percentage of damage mitigation, so player will take less damage from direct attacks overall. Unfortunately, this does not apply to most Area of Effect damage.
You can watch the video below. Paladins: Champions of the Realm is currently in Open Beta on PC, and Closed Beta on PS4 and Xbox One. The PC version recently got its OB46 patch, which added a new character: Lex, The Hand of Justice. You can read more about that patch here.