An apparent grouping of stars (as the Big Dipper) is an asterism, formerly called a constellation. (A constellation is now a bordered area of sky, equivalent to a state on a political map). Stars which are actaully associated, may be a cluster, a nebula or a galaxy.
A loose grouping of a few thousand stars is called a cluster. The stars in a cluster have similar characteristics, which means that they have a common origin.
I think you are referring to a cluster of stars.
Galaxies.
Galaxies.
A misty group of stars is referred to as a star cluster. Star clusters are groups of stars that are gravitationally bound together and can be classified as either open clusters (loose grouping of stars) or globular clusters (more densely packed grouping of stars).
A grouping of stars is called a constellation. Constellations are patterns of stars in the sky that are named after mythological figures, animals, or objects. They help us navigate the night sky and tell stories from different cultures.
Grouping of stars in constellations is completely arbitrary as it depends solely on our point of view (stars in particular constellation aren't really near together and can be separated by great distances - in fact stars belonging to two different constellations may be closer together than stars in just one of them) and was influenced by our mythological views. Grouping of planets in a solar system at least has an actual basis: planets are gravitationally bound to a star and are located nearby.
Grouping stars by brightness
A constellation is a grouping of stars that people say looks like a person or a an object.
They are a less formally defined grouping of stars.
Depending on size, that's probably either a globular star cluster (a vaguely spherical grouping of tens of thousands of stars within a galaxy), or a galaxy (an elliptical, disc-shaped or irregular grouping of billions of stars - including several globular clusters).
We use the word "asterism" for a grouping of stars that isn't one of the 88 "official" constellations recognized by the International Astronomical Union, the IAU. The most famous asterism is the central part of Ursa Major; we call it the "big dipper".