Answer:
The edge of earth and bread.
What you do to determine the length of something
What has black spots and a white face, is fat not thin, and helps you to win, but tumbles all over the place?
Passed from father to son and shared between brothers, its importance is unquestioned though it is used more by others.
When I type I tap these on the keys
Cycle Cycle Cycle.
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?