What's the difference between a word and byte?

Question

I\'ve done some research. A byte is 8 bits and a word is the smallest unit that can be addressed on memory. The exact length of a word varies. What I don\'t understand is wh

Answer 1

It seems all the answers assume high level languages and mainly C/C++.

But the question is tagged "assembly" and in all assemblers I know (for 8bit, 16bit, 32bit and 64bit CPUs), the definitions are much more clear:

byte  = 8 bits 
word  = 2 bytes
dword = 4 bytes = 2Words (dword means "double word")
qword = 8 bytes = 2Dwords = 4Words ("quadruple word")