What Causes Different Stars To Appear At Different Times Of The Year?

Well, since there are two major motions affecting the Earth: Its rotation around its
axis, and its rotation around the Sun (which we call 'revolution').
While the rotation of the Earth on its axis causes the nightly movement of
the stars across the sky, the revolution is responsible for the fact that
we can see different parts of the sky/stars at different parts of the year.

It takes the Earth 1 year to revolve around the sun, in turn, the Earth itself is rotating 1 time per day. Thus we have two main seasons, and to seasons of transition.
At certain times of the year, you can see southern stars, and in the other half of the year, you see the northern stars, because of the Earth's rotation around the sun, and taking a year to do so. Hope this helps.