Which PCI-E slot do I use for soundcard?

Why does this PC fit into a PCIe slot? #SHORTS #pcbuilding pc pcie slot 4-Slot PCIe Expansion Chassis, External PCIe Slots for DesktopServer, PCIe w10Gbps Throughput, PCI Express Expansion BoxAdapter, pcb slot connector Up until a few years ago it was in German and English, I saw one on my home PC and the other at work, with no option to choose language Now

pcmcia slot Up until a few years ago it was in German and English, I saw one on my home PC and the other at work, with no option to choose language Now