This is an excellent example of a globular cluster , a group of about 300,000 stars which is gravitationally bound  to our Milky Way galaxy.   Globular cluster stars are relatively old compared to the Sun, and most would have formed at a similar time, about 12 to 14 billion years ago.  There are 200 - 300 of these globular clusters orbiting the centre of the Milky Way.  Messier 13 is in the direction of the constellation of Hercules and is about 25,000 light years from Earth.