I am new to PCIe. I would like to understand 256 (bus), 32 (device), 8 (function). I am trying to visualise these PCIe slots on a motherboard. I am used to desktop motherboards where we have one PCIE_16, two PCIE_8, and two PCIE_2 slots.
How can a motherboard contain 256 bussesbuses (slots)? How can 256 bussesbuses and 32 devices be connected to a motherboard?