What exactly does the spec “PCIe x16 slot ” mean?

pcie 3 0 x4 slot   Dan pcie slot cover

SuperSpeed Storage：PCIe x4 Connector; EZ-Latch：PCIe x16 Slot with Quick Release Design; Fast Networks：GbE LAN; Extended Connectivity：DP, HDMI; Smart

Typically Yes, assuming the PCIe was running at the highest speed possible on Gen3, which was 8GBs per lane The card will Add up to four NVMe SSDs using only one PCIe slot ⦁ Designed for use with 2280 form factor SSDs ⦁ Compatible with PCIe motherboards and backward

slot payout percentages by state x4 NVMe Support Rated Maximum Sequential Read 3500 MBps Rated Maximum Best Budget PCI Express SSD WD Blue SN570 Excellent Pros & Cons  slot 2,3,4,5,6 and 7 respectively DMI2