PGA socket
Pin Grid Array — a CPU design where the pins sit on the processor itself and press down into holes in the motherboard socket. AMD used it for a long time (all the way to AM4). The downside is well known: bent CPU pins if you're careless.
Mechanic: the processor has a grid of metal pins that fit into corresponding holes in the socket, often with a lever that locks (ZIF). Win: a replaceable CPU, a cheap socket. Classic risk: the pins are on the expensive CPU → if you drop or bend them, it's the processor that gets damaged (the nightmare of removal where the CPU gets stuck in the cooler). The opposite is LGA, where the pins instead sit in the socket (then the motherboard is the sensitive part). AMD switched from PGA (AM4) to LGA with AM5, moving the "pin risk" to the motherboard. Distinct from BGA (permanently soldered). Related to LGA socket and ZIF.