Constellations are groups of stars that we gave names to.
On a really dark night, you can see about 1000 to 1500 stars. To be able to tell the difference between the stars, it helps to break them up into sections that become constellations.
What is a constellation?
There are 88 constellations, all with different patterns, stars and stories that go with them.
Same constellation-Different depictions.
A few constellations are not made up of stars, in the Southern Hemisphere some constellations are instead made of sections of the milky way. An example is the Emu in the Sky.