rearend help...

hey im pretty new at all this stuff was wondering if some one could explain to me how a rear end works ive heard of 4.1 gear ratio is what my truck has.. i think does that mean that for 4 drive shaft rotations my tires turn once?? maybe a dumb question thats what id like to know thanks for any help i can get not sure if this is the rite forum to post in either...??? lol

Basically, there are two main gears in the axle assembly. The gear ratio is the amount of teeth on one gear as compared to the other. A 4.1:1 ratio means that for every 4.1 driveshaft revolutions, the axles turn once.

http://auto.howstuffworks.com/differential.htm