A pillow block bearing, also known as a plummer block bearing, is a specialized type of bearing designed to provide support and easy mounting for rotating shafts. It consists of a housing (the "pillow block") and an insert bearing that fits into the housing. The housing is typically a rectangular or cylindrical structure with a flat base, allowing it to be bolted or mounted onto a surface. The insert bearing within the housing facilitates smooth rotation and supports radial loads, allowing the shaft to rotate while minimizing friction.