The two most common types of expansion slots are Peripheral Component Interconnect (PCI) and Accelerated Graphics Port (AGP).
PCI (Peripheral Component Interconnect ) slot
Can hold a variety of expansion cards such as a sound card or an Ethernet card
AGP (Accelerated Graphics Port) slot
Primarily used for graphics cards
PCMCIA (personal computer memory card international association) slot
Used for laptops in place of PCI slots on desktop computers
Relatively smaller than a PCI slot