Master – Detail Relationship :
- If we delete master records then detail (Child) records are deleted.
- It creates the parent(master) child(Detail) relationship between objects.
- Child records do not have Owner fields it takes parents records owner as child records owner.
- We can have maximum 2 master details on an object
- Roll up summary can be made in Master - child relation
- Standard objects can never be on the detail side of the master detail relationship
- parent is required field while creating child record.
Look up relationship :
- Look up relationship creates relations between two objects.
- If we delete any object then other object is not deleted.
- We can have maximum 25 lookup on an object.
- Roll up summary is not valid.
- standard objects'detail side not possible of the master detail relationship .
- Parent is not required while creating child record.