A Literal is a string that contains a character, a number, or a date that is included in the Select list and which is not a column name or a column alias.
Also note that, Date and character literals must be enclosed within single quotes (‘ ‘), whereas you don’t have to do that for the number literals.
For example: Select last_name||’is a’||job_id As “emp details” from employee;
In this case, “is a” is literal.
