What is the difference between IN and EXISTS in SQL?

• IN: Checks whether a value is present in a list or a subquery’s result set.
• EXISTS: Checks whether a subquery returns any rows, returning TRUE if the

subquery returns one or more rows, otherwise FALSE.

Example with IN:

SELECT name

FROM employees

WHERE department_id IN (SELECT id FROM departments WHERE name =

'HR');

Example with EXISTS:

SELECT name

FROM employees e

WHERE EXISTS (SELECT 1 FROM departments d WHERE d.id =

e.department_id AND d.name = 'HR');