A roof overhang is called an eave. An eave is the edge of a roof that projects beyond the face of a wall, providing protection from the elements.
Eaves are located at the bottom edges of a roof. Eaves normally project beyond the side of the building, forming an overhang. Their primary function is to direct rain water off the walls and to prevent the ingress of water at the junction where the roof meets the wall. Eaves may also protect a pathway around the building from rain, prevent erosion of the footings and reduce splatter on the wall from rain as it hits the ground.