No, Byte = 8 bit (it would be better to say that often byte = 8 bit, but not always)... That is all. Word is a term that associate with internal architecture of processor. For example for 32-bit processor (means that internal registers of processor are 32-bit wide) Word = 32 bit (therefore HalfWord = 16 bit and DoubleWord = 64 bit, QuadWord ...).