Groups of stars have different names depending on the size and nature of the group. A "really big bunch" of stars is a galaxy. A cluster of stars within a galaxy that are "sort of near each other" might be called a local group. There are examples where several stars might form what is called a multi-star system where they all rotate about a common "gravimetric center".
a group of stars is galled a constellation
The group is known as a constellation.
it is called a nebula
I think you are referring to a cluster of stars.
The group of stars is called Constellation. I think it's cluster.
a nebula
A galaxy of stars
An Asterism.
gxpress
It is called a constellation.Constellations.Technically an asterism, but most people usually call it a constellation.
The Milkyway
constellation