robertferanec , 07-18-2020, 03:16 AM
Manufacturing different versions of PCB is very expensive. It is much easier to have one PCB and just fit / unfit some components to get different variants of your board.
There are many components on boards what are not fitted. For example, if you would like to make a cheaper variant of your board - you do not have to fit some block. Variants can be used also to replace components, again, you can have an expensive board with big memory or a cheap one with small memory - still using the same PCB.
Also, many times you have on board components which are used for testing but will not be used in production - again something when variants are useful.