Question

explain why do stars twinkle​

Answer 1

Stars twinkle because of turbulence in the atmosphere of the Earth. As the atmosphere churns, the light from the star is refracted in different directions. This causes the star's image to change slightly in brightness and position, hence "twinkle."

Answer 2

stars twinkle due to refraction in the atmosphere.

The atmosphere has many layers of different densities and optical densities.

So they refract the light coming from stars.

So the actual position of stars is not what we see as they appear to be shifted from their position.