Difference between a view and a base relation

Difference between a view and a base relation: -

Views:
1. This is one type of relation which is not a part of the physical
database.
2. It has no direct or physical relation with the database.
3. Views can be used to provide security mechanism.
4. Modification through a view (e.g. insert, update, delete) generally
not permitted

Base Relation:
1. A base relation is a relation that is not a derived relation.
2. While it can manipulate the conceptual or physical relations stored
in the data.
3. It does not provide security.
4. Modification may be done with a base relation.

We can assign the view, a name & relate it the query expression as
Create View <View Name> as <Query Expression>
Let EMPLOYEE be the relation. We create the table EMPLOYEE as follows:-

Create table EMPLOYEE
(Emp_No integer of null,
Name char (20),
Skill chars (20),
Sal_Rate decimal (10, 2),
DOB date,
Address char (100),)
For a very personal or confidential matter, every user is not
permitted to see the Sal_Rate of an EMPLOYEE. For such users, DBA can
create a view, for example, EMP_VIEW defined as:-

Create view EMP_VIEW as
(Select Emp_No, Name, Skill, DOB, Address
         From EMPLOYEE)