I never thought I'd find myself answering this one but...

A bit is the smallest variable you can have... represented by one wire, one pin, one-eighth (1/8) of a byte... in the Digital world, this can only be Zero (0) or One (1)... there is no other state.

So the variable range for a BIT is 0-1. It's either a Zero or a One, that's it...

Like I always say to everyone... if you can count to ONE, you're a computer expert, because that's all ANY Digital computer does... it just might happen to do it damn quick, but basically if you can understand that concept, then that's all there is to computers... micro, mini or mainframe... if you can count to one (or have an IQ equal to or greater than a BIT), you too can earn big bucks...