The scientific term for a group of stars is a "star cluster." Star clusters can be categorized into two main types: globular and open clusters. Globular clusters are densely packed groups of thousands to millions of stars, often found orbiting the galactic core. In contrast, open clusters are more loosely associated, typically containing a few dozen to a few thousand stars, and are often found in the arms of spiral galaxies. Studying star clusters helps astronomers understand stellar evolution, dynamics, and the formation of galaxies.