Use of With Clause in SQL Server

Question

How does with clause work in SQL Server? Does it really give me some performance boost or does it just help to make more readable scripts?

When it is ri

Answer 1

with is a keyword in SQL which just stores the temporary result in a temporary table. Example:

with a(--here a is the temporary table)
(id)(--id acts as colomn for table a )
 as(select colomn_name from table_name )

select * from a