Globular clusters are much denser and contain many more stars than open clusters. Here's a breakdown:

* Globular clusters:

* Contain hundreds of thousands to millions of stars.

* Are tightly packed and spherical.

* Are very old, dating back to the early universe.

* Are found in the halo of galaxies.

* Open clusters:

* Contain a few hundred to a few thousand stars.

* Are less densely packed and have a more irregular shape.

* Are younger than globular clusters.

* Are found in the disk of galaxies.

So, while both are star clusters, globular clusters are far more massive and contain significantly more stars than open clusters.