What is an slot on a motherboard used for?

m2 pcie slot   Dan m24 slot

Enjoy extremely fast transfer speeds via PCIe lanes Includes a heatsink and thermal padding SSD bus interface: NVMe

2 standard contains variants with up to four PCIe lanes, one SATA 6 Gbs and or one USB port So it is possible to connect PCIe as well as SATA SSDs  Utilize an available PCIe x4 expansion slot for the installation, removal, or interchange of PCIe SSDs The drive tray accommodates M-Key NVMe SSDs

100 burning hot slot 2 standard contains variants with up to four PCIe lanes, one SATA 6 Gbs and or one USB port So it is possible to connect PCIe as well as SATA SSDs  2 slots are similar to PCIe expansion slots but are much smaller And this makes them perfect for SSD drives with a form factor similar to a RAM stick