There are three different versions of the Raspberry Pi 4 out on the market right now: the “normal” Pi 4 Model B, the Compute Module 4, and the just-released Raspberry Pi 400 computer-in-a-keyboard.
The Raspberry Pi Compute Module 4S is a SODIMM-style version of the Compute Module 4. It has the same processor as the standard model, but the form factor restricts the I/O capabilities, so it’s not ...