A view is a database object that represents the data in one or more tables in the same structure as a separate table. Here are some basic rules about views:

* Tables store real data.

* Views do not store real data.

* Views must have underlying tables to provide data.

* Each view is based on a single SELECT statement to control what data to collect from tables, and how data should be represented.

* View's columns can be mapped directly to columns in underlying tables.

* View's columns can be created expressions based multiple columns in underlying tables.

* Views can be used in same way as tables in queries.