slots had 4 PCIe lanes, so is the M.2 separate to those other PCIe slots or would an SSD using the M.2. have to interface with one of those slots too? If the latter, my desktop has no GPU so presumably it could
Motherboards allow various protocols to run in a system at the same time. Protocols from DDR3 and DDR4 for connected hard drives and DDR5 for graphics, PCIe (NVM Express) for Flash storage, and SPI and I2C for the low-level board and system operations, these protocols run on the same ...
DDR2 is quite outdated, so you're unlikely to come across it now. You'll still see DDR3 RAM around, but it's mostly been superseded by DDR4, which is the current standard. While DDR5 is on the way at the time of writing, it's not commercially available yet. Different generations ...