Peripheral Component Interconnect or PCI cards refer to the local computer bus used for attaching the hardware devices within the computer. It is the part of the PCI Local Bus standard which supports the functions found on the processor bus in a standardized format. Every computer comes with two primary buses, which remain interlinked to the central processing unit. The system bus is the fastest as it connects the main memory or RAM with the CPU. Therefore, PCI is ideal for facilitating the communication of hardware devices, including graphics, video, audio, network, etc., with microprocessors.