What they are

Constellations are what we see in the night sky.
They form together animals, gods and mythical creatures.
They all represent different dates.
For example if you are born on June 17th you are a Gemini,
but if you are born on August 14th then you are a Leo.

Are stars near each other in constellations?

The stars in constellations are not always near each other which is surprising.
Each constellation is a collection of stars that are distributed in space in three dimensions
The stars are all different distances from Earth.