What is PCIe x16

This topic describes how to use the PCIE x16 slot？ pcie x 16 slot Also I forgot to say before I went to bed last night since it works as it should in the second PCIE x16 slot I would replace the Motherboard pcie x32 slot Have you ever thought if you can plug PCI Express cards into x16 lane slot? In this video

pcie x1 slot function Two types of PCIe slot on an Asus H81M-K motherboard Various slots on a computer motherboard, from top to bottom: PCI Express x4; PCI Express x16; PCI Express