A pin header is a type of electrical connector commonly used on printed circuit boards (PCBs). It consists of a series of metal pins arranged in a row, which can be inserted into a matching socket or connected to other components. Pin headers are often used for connecting wires, sensors, or other devices, making them essential in various electronic applications. These connectors come in different configurations, including single-row and double-row designs, and can vary in pin spacing. They are widely used in devices like Arduino boards, Raspberry Pi accessories, and other DIY electronics projects, providing a reliable way to establish connections.