The primary role of the Parliament is to discuss, debate, and pass bills. Once passed, a bill becomes an Act of Parliament. An ordinary bill can be introduced in either house — Lok Sabha or Rajya Sabha (unlike a finance bill). It then has to be approved by both houses, and signed by the President. If the two houses disagree on the bill, or if six months have passed since its receipt by the second house, the President may call a joint session to vote on it. Finally, when the Lok Sabha is dissolved, bills introduced in the Lok Sabha or pending there lapse and must be re-introduced.