Abaid-ur-Rehman Zulfi
Said..
A clustered index is a speical type of index that orders the records in the way they are stored physically on the disk. A table can have only one clustered index. The leaf nodes of clustered index contain data pages.
A non-clustered index is a specail type of index in which logical order of records don't match with physical order of records. A table can have multiple non-clustered indexes. The leaf nodes contain index rows.