pci slotWhat is a PCIe card? A PCIe card, also known as a PCI Express card, is an expansion card that connects to a computer's motherboard using a PCIe slot.Learn about the different types of slots on the motherboard, such as PCI, PCIe, PCI-X, AGP, ISA, EISA, VESA, RAM, AMR and CNR. Find out their purposes, features,