A DBA or database administrator is a technical wizard who manages the complete operation of the Oracle database. A table is a database object that holds your data. A table is made up of many columns, each of those columns has a data type associated with it. A view allows you to see a customized selection of one or more tables, and it uses a SQL query that is stored in the database. When using views, the SQL statement that defines the view is executed as if you had coded the defining statement yourself.
Views can provide an additional level of security.
Views allow you to hide data complexity. Views help you maintain naming sanity. Index entries for a table allow Oracle rapid access to the data in your tables. A synonym is an alternate name for an object in the database. Think of a synonym as a nickname for an object.