A lot of couples prefer two photographers. The main photographer is referred to as the primary shooter. And the extra photographer is referred to as the second shooter.
While, some photographers work in teams, others hire second shooters as needed.
So sometimes, I am called upon to fill the second shooter shoes. Which is actually a lot of fun. While the primary shooter is expected to get all the important photos. The second shooter works under a lot less stress to come up with photos of unexpected moments and photos of expected moments from a different angle.