8 bit processor

what is mean by 8bit,16bit, 32bit microprocessor.what is describing this bit size. plz explain in detail

The size describes the capacity of microprocessor to perform the arithmatic & logical operations. It means that 8-bit microprocessor can do arithmetic & logical operations directly on 8-bit numbers, but it cant perform such operations on 16-bit numbers. Similarly, 16-bit & 32-bit microprocessor can do perform such operation on 16 bit & 32 bit numbers respectively.

And one more thing I forgot to tell is that the size of microprocessor registers are fixed and is describe by the 8-bit, 16-bit, or 32-bit. Or we can say more generally that this size describes the length of the accumalator.