Which type of socket use pins on the bottom of the processor?

The type of socket that uses pins on the bottom of the processor is known as a PGA (Pin Grid Array) socket. In this design, the CPU has multiple pins that fit into corresponding holes in the socket, allowing for a secure connection and electrical contact. This is commonly used in various Intel and AMD processors, particularly in older models. The PGA socket contrasts with LGA (Land Grid Array) sockets, where the pins are located on the socket itself, and the CPU has flat pads.