This Master-Detail relationship is the same as the relationship between a parent & child. In this aspect, the master is treated as Parent, and the Detail is a child. The master Object takes control over the behaviour of the Detail object. Survival of the child is dependent on the parent because if the Master get deleted the Detail will also automatically get deleted. You can create Roll-up summary fields in master records which helps in calculating the Min, Avg, Sum of the child records.