"Maintenance rehearsal" is a shallow form of processing information which involves focusing on an object without thought to its meaning or its association with other objects. For example, the repetition of a series of numbers is a form of maintenance rehearsal. In contrast, "elaborative or relational rehearsal" is a process in which you relate new material to information already stored in Long-term memory. It's a deep form of processing information and involves thought of the object's meaning as well as making connections between the object, past experiences and the other objects of focus. Using the example of numbers, one might associate them with dates that are personally significant such as your parents' birthdays (past experiences) or perhaps you might see a pattern in the numbers that helps you to remember them.