A spherical collection of stars, the concentration of which increases greatly toward the center: All of the stars in the globular cluster are probably of the same age, and the densely-packed group, as a whole, moves in highly elliptical orbits that take them high above the galactic center.

A globular cluster is a dense group of thousands to millions of stars.

All the stars in a spherically symmetric collection, or a globular cluster, have shared a common origin.