"Float
A property of a clipless pedal system that allows the rider to rotate the foot within limits, as opposed to a fixed cleat which holds the shoe at a fixed angle in the yaw axis.
Pedals with float allow you to rotate your heel inward or outward to some extent before disengaging the cleat."

Sorry if I confused you. Go to Sheldon Brown's glossary for definitions of bicycle terms. The rest of the website has tons of basic information for all knowledge levels and may answer a lot of your questions.

http://sheldonbrown.com/glossary.html