what are the advantages by using views in real time applications and views or recommended or not?

Views also can query more than one table for the data you are creating the view for. So, this helps the developer not to query multiple tables for the required data along with that Views provides security to the data and tables. A developer may have only execute permissions on the view and he may not be able to read the content and so, the table structure and data are hidden from the developer. Only developer understands that he has to use a particular view for the data he wanted.

Views help prevent data from unauthorised access. User is allowed to view only that much data which is necessary and allowed by database administrator. View also help comforting the user. Use of views is highly recommended for purpose of improving security,simplicity and selective authorization .