what is the meaning of the last letters (IBPW, IBPWG4, IBPWR and IPW, IPWG4, IPWR) on the components??

Splitting this thread.

I assume you mean the writing on the other parts (not the Hercules MCU but the smaller ones)?   those last letters are usually package designators. But the symbolization can be a little different for each device.

You can also look at this page for packaging information.   For example, the PW package is usualy an SOIC type.