PCBA means PCB Assemblies.

A printed circuit board (PCB, also printed wiring board or PWB) is a medium used in electrical and electronic engineering to connect electronic components in a controlled manner. It takes the form of a laminated sandwich structure of conductive and insulating layers, among these layers, each of the conductive layers is designed with an artwork pattern of traces, planes and other features (similar to wires on a flat surface) etched from one or more sheet layers of copper laminated onto or between sheet layers of a non-conductive substrate.

Electrical components may be fixed to conductive pads on the outer layers in the shape designed to accept the component terminals(generally using soldering) to both electrically connect and mechanically fasten them to it.

When some electronic components together to form a functional printed circuit assembly (PCA), this is called a "printed circuit board assembly" (PCBA).