What are the various indexes in Teradata? How to use them? Why are they preferred?

The index is an important aspect of database design used in Teradata.The various types of Indexes used in Teradata are:

No primary index -  The absence of a primary index is counted as No primary Index.

Primary indexes - The primary index value is set to determine on which AMPS the rows of a primary‑indexed table are to be stored.

Hash and join indexes - The various join indexes are not necessarily mutually exclusive types.

Secondary indexes - It includes Unique, Nonunique hash‑ordered on all columns with the ALL option, etc.