The black robe or garment worn by Catholic priests is called a cassock or soutane. Cassocks worn by Catholic priests can have up to 33 buttons located on the front of this garment. Catholic priests also wear different liturgical vestments to say Mass, such as the chasuble, amice, cincture, dalmatic and alb.
A chasuble is a garment worn over other liturgical vestments like the alb and cincture. The alb is a white linen robe that is long and the cincture is the rope-like belt worn around the waist to secure the alb.
In the Catholic Church, cassocks can be different colors. For example, bishops wear purple and cardinals don red cassocks. The Pope wears a white one. Although Catholic priests wear these garments, other denominations like Anglicans also may wear cassocks.