What is the difference between a White Leghorn and a White Rock?

[WhiteLeghorn]

What is the difference? I know that their colors are white but I am having a hard time identifying my two white chckens.

 

[kathyinmo]

white leghorn ear lobes should be enamel white.
white rocks ear lobes should be bright red.

 

[Bantimna]

Quote:
White Leghorns have a lighter frame than White Rocks
White Leghorns lay white eggs and white rocks lay brown eggs