Relationship

1. Lookup(1:n)
2. Master Detail(1:n)
3. Many to Many(m:n)
4. Self or hierarchical(1:1)

Lookup

1.Relation field is optional. 2.If you delete the parent record child record still exists. 3.Parent Record owner and child record owner can be different User.

4.Value of relationship field will be NULL. 5. No Inheritance. 6. 1:n(50,000)

Master Detail(M:D)

1.Relationship Field is Required. 2.If you delete the parent record all the child records will be deleted. cascading delete