curious48:
This is a detailed answer but I believe it is mistaken.
You have really got a lot of nerve.
You ask a question, then you have the audacity to say that the answer you received is wrong? ? ?
HUH.
If you already know the answer, don't bother coming here. It simply wastes people's time.
By the way, the full answer that marco_c gave is It is a subset C++ with library extensions that simplify access to hardware functionality. Your learning to read would help too.