SQL Server - Difference between Primary Key and Foreign Key

The below are the key differences between PK and FK.

S.No	Primary Key	Foreign Key
1	Primary key uniquely identify a record in the table.	Foreign key is a field in the table that is primary key in another table.
2	Primary Key cannot accept null values	Foreign key can accept multiple null values.
3	By default, Primary key is clustered index and data in the database table is physically organized in the sequence of clustered index.	While Foreign key is non-clustered index.
4	We can have only one Primary key in a table.	We can have more than one foreign key in a table.