PCI Express also called PCIe
PCI Express is the next generation local interconnect on a motherboard. It effectively started supplementing the older PCI and AGP bus and has become the prevailing interconnect standard. End users in general get in general associate with PCI Express a graphics card slot on the motherboard. Here PCIe x8 or PCIe x16 are the most seen standards. PCIe in the meantime has replaced the AGP slot for graphics cards.