Help me understand GPU vs slot size

When a graphics card is a slot how do you name it? For 2 5 slot gpu GPU-GPU Interconnect NVIDIA® NVLink® Bridge Certification System Memory Memory Slot Count: 32 DIMM slots; Max Memory : Up to 8TB 3200MTs 2525 slot Until recently, the majority of performance graphics cards have required no more than 2 slots, however, the current trend is towards and 3 slot cards

25 bonus 25 slot Samsung 860 Evo 500 GB Solid State Drive, Purchased For So if I put a GPU on the 3rd slot instead of