Joint session

A joint session or joint convention is, most broadly, when two normally-separate decision-making groups meet together, often in a special session or other extraordinary meeting, for a specific purpose.

Most often it refers to when both houses of a bicameral legislature sit together. A joint session typically occurs to receive foreign or domestic diplomats or leaders, or to allow both houses to consider bills together.

United States

The State of the Union Address of the president of the United States is traditionally made before a "joint session" of the United States Congress. Many states refer to an analogous event as a "joint convention". Obviously such assemblies are typically held in the chamber of the lower house as the larger body.

State constitutions of U.S. states may require joint conventions for other purposes; for example Tennessee's requires such to elect the secretary of state, the state treasurer, and the comptroller of the treasury.

Others

In another analogous but not identical event, the monarch's speech upon the opening of the British Parliament is made before a joint sitting of the Commons and the Lords, but this event occurs in the Lords' chamber, both because it was formerly the larger body but also due to the constitutional convention that the monarch never enters the Commons chamber.

Various government agencies and non-governmental organizations may also meet jointly to handle problems which each of the involved parties has a stake in.