Whats the Difference between Cluster and Non-cluster index ?

Clustered Index

* There can be only one Clustered index for a table
* Usually made on the primary key
* The logical order of the index matches the physical stored order of the rows on disk

Non-Clustered Index

* There can be only 249 Clustered index for a table
* Usually made on the any key
* The logical order of the index does not match the physical stored order of the rows on disk