The PCI bus (Peripheral Component Interconnect bus) is a standard interface used to connect various hardware components in a computer. It allows devices like graphics cards, network cards, and storage controllers to communicate with the computer's central processing unit (CPU) and memory. The PCI bus supports multiple devices on the same bus, enabling efficient data transfer and resource sharing. Introduced in the early 1990s, the PCI bus has evolved into several versions, including PCI Express (PCIe), which offers faster data rates and improved performance. This technology is essential for modern computing, as it facilitates the integration of various peripherals, enhancing overall system functionality.