"Periphery equipment" is electronic equipment that can be plugged into a computer using one of its input/output interfaces (serial port, parallel port, USB bus, FireWire bus, SCSI interface, etc.), most often by using a connector. Periphery equipment is therefore external computer components.
Periphery equipment is generally grouped into the following categories:
An "expansion card" is electronic hardware in card form that can be plugged into a computer using an expansion connector (ISA, PCI, AGP, PCI Express, etc.).
Expansion cards are components that are connected directly to the motherboard and are located in the main unit, giving the computer new input-output functions.
The main types of expansion cards are: