What are the difference between clustered and a non-clustered index?
A clustered index is a special type of index that reorders the way records in the table are physically stored. Thus table can have only one clustered index. The leaf nodes of a clustered index have the data pages.
A non clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk. The leaf node of a non clustered index does not having of the data pages. Instead, the leaf nodes have index rows.