Peripheral Component Interconnect (PCI) is a standard for connecting hardware components in a computer. It allows various devices, such as graphics cards, network cards, and storage controllers, to communicate with the computer's central processing unit (CPU). PCI slots are typically found on the motherboard, providing a way to expand a computer's capabilities by adding new components. Introduced in the early 1990s, PCI has evolved into several versions, including PCI Express (PCIe), which offers faster data transfer rates and improved performance. This technology is essential for modern computing, enabling efficient communication between the CPU and peripheral devices, thus enhancing overall system functionality.