Here's the breakdown:

* Star cluster: A group of stars that are gravitationally bound together. They can be either open clusters (loosely bound, young stars) or globular clusters (tightly bound, old stars).

* Constellation: A pattern of stars that humans have named and recognized for centuries. They are not physically connected, but appear close together from our perspective on Earth.

So, while star clusters do contain stars, they don't necessarily form recognizable patterns like constellations.