A PCB with components soldered on. "Bare PCB" + reflow = PCBA.
How it looks
Real image: CORE3588, rendered by KiCad from our board file
CORE3588 with its parts soldered on: the same board as on the PCB card, now a PCBA. The two long rows of bare pads in the middle are left empty on purpose: the computer module plugs into sockets there and is not part of this board.
1The Wi-Fi chip module (ESP32), a whole small board soldered on.
2The USB-C socket.
3One of six camera cable sockets.
4The micro SD card holder.
Real image: CORE3588, rendered by KiCad from our board file
The same assembled board from an angle, so the height of the parts shows.
How it works
Where it fits
PCBA = PCB + parts. The parts list is the BOM, their positions the CPL; JLCPCB or PCB Power do the assembly.