A dense spherical grouping of stars bound together by their own gravity. Globular clusters are very old and found in the halo orbiting galaxies. Our Milky Way has some 200 globulars, examples include Omega Centauri, 47 Tucanae, M4 and M13.
The Andromeda Galaxy (M31) has at least 500 globulars but this number is small compared to giant elliptical galaxy M87, which contains at least 12,000.