A discrete group $G$ acts properly discontinuously on a manifold $M$ if the set $\{g\in G\mid gK\cap K\neq \emptyset \}$ is finite.

Is there a more abstract characterisation of this property?

I am looking for something that looks like a diagram, a functor or anything vaguely related (to homological algebra, category theory). I have had a look at the relevant pages on nlab, but, although there is a description for a proper map of schemes, I can't think of any formal way of characterising a proper map of topological spaces.

(As I have little working experience with schemes, I would also welcome and be grateful for any comments that would shed light on why the characterisation for schemes is an analogue to proper maps of topological spaces.)