ALIASES in Oracle helps to create provide a temporary name to a column or table in a database just to make it easily understandable. Keyword AS is used to describe an Alias in Oracle. ALIAS in Oracle is performed in two different ways. Follow the below syntax to understand ALIAS in a better way.
Syntax
For suppose we have Stu Table as Shown below:a

1). By using AS
select name as first_name from Stu;
2). Without using AS
Select name First_name from Stu;
Example
Select name AS First_name from Stu;
Output
You will get the same output using both the syntaxes above:
NOTE: You can also set ALIAS for Table as a whole. Follow the below syntax for the same:
Select name from Stu Student;
Output