What are PCIe x1 Slots Used For?

Oleg Kasich ; Expansion slots, 1×PCI-E x16; 1×PCI-E x16 ; 1×PCI-E x1 ; Storage devices, 1× PCI-E x4; 3× PCI-E

This is a dual slot card, meaning it covers the first available PCIe 1x slot I have a PCIe 1x Firewire card and a PCIe 1x WiFi card Both cards function fine

pcie 4 card in pcie 3 slot I recently swapped out my old MB for a MSI MEG X570 Unify motherboard and and now my Intel Wi-Fi 6E AX210 based PCIE Adapter won't function

pcie gen 4 in gen 3 slot M · NVME Adapter PCI-E x1 to M · NVME M · Dual Slot M · NVME SSD M2 PCIE 1x Adapter PCIE To M2 Adapter M · Multi-Function USB Hub eSATA SATA Port