I don't understand this part:

'Well, a bit is a 0 or 1. A byte is 8 bits: 0000 0000 through 1111 1111. The first four bits give you a range of 16 possibilities. The second four bits also give you 16 possibilities. So if you have 16 times 16 combinations, that gives you 256 possibilities. Or a byte.'

I don't understand why the first four bits give a range of 16 possibilities. Does all four bits give 16 possibilities? Can anyone tell me?

0000 (0)
0001 (1)
0010 (2)
0011 (3)
0100 (4)
0101 (5)
0110 (6)
0111 (7)
1000 (8)
1001 (9)
1010 (10)
1011 (11)
1100 (12)
1101 (13)
1110 (14)
1111 (15)

Sixteen possibilities, counting from 0. Note how every power of two adds another bit to the left: 1, 2, 4, 8, 16, etc.

 

(You forgot to click Don't use smileys)

Thanks! I can understand now.