Temporary tables in SQL are used for manipulation of data for a short period of time.

It can be used as a accumulator like we have in microprocessor which acts as mediator to store and perform operations into it.

Temporary table in SQL are mainly of two types:

LOCAL TEMPORARY TABLES

GLOBAL TEMPORARY TABLES

Local Temporary Tables have scope within the window in which it is created and used

For ex :
DECLARE LOCAL TEMPORARY TABLE studentdetails
( id int NOT NULL,
  name varchar(50) ,
  contact varchar(50)
);

Global temporary table can be used outside the query window where is it has been created.

For ex:
CREATE GLOBAL TEMPORARY TABLE suppliers
( supplierid int  NOT NULL,
  suppliername varchar(50),
  contactname varchar(50)
);