What are PostgreSQL stored procedures and how do they differ from functions?

Stored Procedures (PostgreSQL 11+):
• Can manage transactions
• Support COMMIT/ROLLBACK
• Called with CALL statement
• Cannot return values directly

Functions:
• Cannot manage transactions
• Return values or tables
• Called in SELECT statements
• More flexible for calculations

Example Procedure:

CREATE PROCEDURE transfer_funds(
    sender_id INT,
    receiver_id INT,
    amount DECIMAL
)
LANGUAGE plpgsql
AS $$
BEGIN
    UPDATE accounts SET balance = balance - amount WHERE id = sender_id;
    UPDATE accounts SET balance = balance + amount WHERE id = receiver_id;
    COMMIT;
END;
$$;