- A cluster index creates on primary key.
- A cluster index create automatically when primary created on the table.
- There can be only one cluster index per table.
- A cluster index sort and store data in a table based on columns included in index.
- A cluster index takes space of table.
- There can be multiple non cluster index per table.
- Non clustered indexes store both a value and a pointer to the actual row that holds that value.
- A non cluster index takes space on the server.