Anatomy of a Root File
	• Root File is a Random Access Object Store • Objects in file can be looked up by “Key” – Key is a String. – Each key can correspond to a hierarchy of linked objects – TTree objects are special • Can contain multiple branches – Each branch contains » More branches » A set of objects (e.g. Events, Tracks etc). • TTree objects provide random access to events, and allow reading only a subset of branches for efficiency.