Globular clusters are composed of hundreds of thousands of very old stars, all tightly packed in a spherical area located near or in the halo of a galaxy.
M13 shown below is a great globular cluster easily visible in binoculars in the constellation of Hercules.
![Picture](/uploads/7/1/8/4/7184949/9021527.jpg?453)
An Open cluster is composed of hundreds of stars born in the same molecular cloud about the same time.
This is the Pleiads Open star cluster M45. September, 2018