Joint Sitting of Lok Sabha and Rajya Sabha:
If there is a difference of opinion between Lok Sabha and Rajya Sabha over an ordinary bill, the matter can be resolved through a joint sitting of the two Houses. This is provided under Article 108 of the Constitution of India.

Procedure for a Joint Sitting:
1. The President of India has the power to summon a joint sitting of both Lok Sabha and Rajya Sabha. The President can exercise this power if there is a deadlock between the two Houses over the passage of an ordinary bill.
2. Before summoning a joint sitting, the President must inform both Houses of Parliament about the intention to do so.
3. The joint sitting is presided over by the Speaker of Lok Sabha or, in their absence, the Deputy Speaker of Lok Sabha. If both the Speaker and Deputy Speaker are absent, the Chairman of Rajya Sabha presides over the joint sitting.
4. During the joint sitting, the bill is discussed and voted upon. The decision is taken by a simple majority of the members present and voting.
5. If the bill is passed by a simple majority in the joint sitting, it is considered as being passed by both Houses. However, if the bill is rejected or not passed in the joint sitting, it is deemed to have been rejected by Parliament as a whole.

Significance of Joint Sitting:
1. Joint sittings provide a mechanism to resolve differences between Lok Sabha and Rajya Sabha over the passage of an ordinary bill. It ensures that both Houses have an equal say in the legislative process.
2. Joint sittings promote the principle of bicameralism, where both Houses of Parliament have distinct roles and functions. It allows for a comprehensive debate and discussion on the bill, taking into account the viewpoints of members from both Houses.
3. Joint sittings also reflect the democratic nature of the Indian parliamentary system, as decisions are taken by a simple majority of members present and voting.

Conclusion:
In summary, when there is a difference of opinion between Lok Sabha and Rajya Sabha over an ordinary bill, a joint sitting of both Houses can be called by the President. During the joint sitting, the bill is discussed and voted upon, and the decision is taken by a simple majority. The joint sitting ensures that both Houses have an equal say in the legislative process and promotes the democratic and bicameral nature of the Indian parliamentary system.