clusters of stars come in 2 kinds, globular cluster and open clusters.

Globular clusters

Gobular clusters are very closely packed clusters of stars. They are very old, typically more then 10 billion years.

Messier 13 – great globular cluster in Hercules – 2022 (LRGB)
Messier 71 – in the busy background of our own Milky Way (RGB DSLR)
Messier 15 – (RGB with DSLR)

Open clusters

Open clusters are clusters of gravitionally bound stars that have formed from one cloud of gas. They are young (in an astronomical sense). In contrast to globular cluster open cluster are so loosely packed that over time the stars will drift apart and the cluster will generally disolve.

The Pleiades – Messier 45 (LRGB)
M44 – the Beehive cluster in constellation Cancer – in LRGB
NGC 7790 – (AAVSO standard field) in IBV photometric filters (Red replaced by Infrared producing ruby red stars)
Double cluster (chi and h persei) in perseus, LRVB.
Caldwell 1 – (Polarisimo cluster) + 3 variable stars (LRGB)