# Definition:Universe of Discourse

## Definition

The universe of discourse, or just universe, is the term used to mean everything we are talking about.

When introducing the symbols $\forall$ (the universal quantifier) or $\exists$ (the existential quantifier), it is understood that the objects referred to are those in the specified universe. It is usual to define that universe.

## Also known as

The universe of discourse is also known as the universe of interpretation or domain of discourse.