You can use views to focus, simplify, and customize each user’s perception of the database; views also provide an easy-to-use security measure.
Views can also be helpful when changes have been made to the structure of a database, but users prefer to work with the structure of the database they are accustomed to.
Focus on the data that interests each user, and on the tasks for which that user is responsible. Data that is not of interest to a user can be omitted from the view.
Define frequently used joins, projections, and selections as views so that users need not specify all the conditions and qualifications each time an operation is performed on that data.
Display different data for different users, even when they are using the same data at the same time. This is particularly usefull when users of many different interests and skill levels share the same database.