What is the difference between Look Up Relationship and Master Detail Relationship in Salesforce?

Hi Sweta,

Master-Detail Relationship-

1. You cannot have a detail record without a master.
2. The detail record inherits sharing rules from the master.
3. You cannot update the relationship to the master in a master-detail relationship.
4. The number of master-detail relationships you can use are limited.
5. You cannot set profile object permissions for a detail record
6. Master-detail relationships are automatically included in report record types

 LookUp Relationship -

1. Lookups are generally for use where you may or may need to have a relationship between two objects (but not always).
2. Lookups are generally used to reference commonly shared data, such as reference data.
3. Lookups are used to link two objects together when you don't want the behaviour of the master-detail - particularly around sharing rules, profile permissions and cascade delete.
4. Lookups are used when you need to relate multiple 'parents' to the detail record.