Discrete groups, sitting at their tables, not mingling at all; in fact, not even seeming to notice each other.

Discrete groups can therefore be identified with their underlying (non-topological) groups.

Indeed, analysts may refer to the ordinary, non-topological groups studied by algebraists as discrete groups.

The duality interchanges the subcategories of discrete groups and compact groups.

The term subpopulation refers to a discreet group of individuals, separated from other discrete groups within a single watershed.