What is the Difference Between a PCB and PCBA?

PCB is a Printed Circuit Board. It’s an important electronic component, which is a support for electronic components and a carrier for electrical connections between electronic components.
An electronics PCBA is a complete package; it has been fitted with all the necessary components(capacitors inductors, resistors, diodes, triodes, modules, and BGA’s) and is ready for deployment for its desired purpose.
The rigid-flex PCB is often made up of multiple layers with 4 and 6 being the most commonly used, depending on the required number of signal layers.
As it is produced by printing the required image on the substrate, it is called a “printed” circuit board. It’s most commonly manufactured using copper-clad epoxy resin/glass cloth compound.
Blue PCBA is the complete electronic assembly, whereas a PCB fabrication is purely the bare electronic circuitry.
PCBA stands for Printed Circuit Board Assembly and relates to the component placement onto the bare board or PCB. Multiple electronic components are assembled to the circuit board and soldered into position.