In computing, an expansion card is a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer's motherboard to add functionality to a computer system. An expansion slot is used to add an adapter to the motherboard. In computers, a slot, or expansion slot, is an engineered technique for adding capability to a computer in the form of connection pinholes (typically. This article covers expansion cards in. An expansion slot is a socket on the motherboard that is used to insert an expansion card (or circuit board), which provides additional features. Typical slot formats include PCIe and PCI. An expansion slot is a socket on a computer motherboard that allows you to add additional components to your system. The meaning of EXPANSION SLOT is a socket on the motherboard of a computer into which an expansion card may be inserted. In computing, an expansion card is a printed circuit board that can be inserted into an electrical connector, or expansion slot on a computer's motherboard. An expansion slot is a port on a motherboard that accepts an expansion card. Alternatively known as a bus slot or expansion port, an expansion slot is a connection or port inside a computer on the motherboard or riser. It has rules that control how many bits can be transferred at a time to the. . Certain industrial PCs are equipped with expansion slots that can house expanded function boards (expansion cards). These slots are used to expand the.