A PCB header is a type of electrical connector mounted on a printed circuit board (PCB) that allows the board to connect to other components, cables, or additional circuit boards. It consists of a row (or multiple rows) of metal pins embedded in a plastic base, which are soldered directly onto the PCB.

PCB headers are commonly used to transfer power, signals, or data between different parts of an electronic system. They can be paired with matching connectors, such as socket headers or ribbon cable connectors, making it easy to plug and unplug connections without soldering wires directly to the board.

These headers come in various sizes, pin counts, and layouts, including male or female versions, straight or right-angle designs, and single-row or double-row configurations. Their versatility makes them widely used in applications such as microcontroller boards, sensors, programming interfaces, and internal connections in electronic devices.

In simple terms, a PCB header provides a convenient and reliable way to connect a printed circuit board to other electronic components or systems.