parapet, a dwarf wall or heavy railing around the edge of a roof, balcony, terrace, or stairway designed either to prevent those behind it from falling over or to shelter them from attack from the outside.

What is a parapet on a building?

Parapets are aesthetic features of many buildings—typically vertical extensions of exterior walls used to create architectural elements, conceal rooftop mechanical equipment, or perform other functions.

What are the types of parapet?