what does it mean by the sun move eastward with respect to the stars ? wts "with respect to" ?

The sun only appears to move because of its relative distance to us compared to the other stars and because of our own motion through space.

It means that from our point of view, the sun appears to move in the sky when compared to the very distant stars that don't move in our skies.

The sun is closer to the Earth, so as we orbit the sun it appears to have moved against the more distant stars.
Its called "parallax".

Try this - line up some object close to you with something farther away (like a lamp post with a more distant building).
Now, walk to your right a few steps and notice that the lamp post isn't lined up with that building anymore - the lamp post has moved "with respect to the building".

It means if you drew the position of the sun on a star chart, it would move eastward from one day to the next.

"X with respect to Y" in the context of motion means that we CONSIDER object Y to be stationary, and we measure X's motion based upon how it moves as Y would observe X to be.

Suppose there were a boat on the water. This boat can 10 meters per second if the water is still. BUT, the boat is moving through water that actually has a current. The speed of the water relative to the seabed is 5 meters/second.


If the boat travels IN the direction of the water's current, then the boat's speed with respect to the seabed is 15 m/s.

If the boat travels OPPOSITE the direction of the water's current, then the boat's speed with respect to the seabed is 5 m/s.

In any case, the boat's speed with respect to the water is 10 meters per second.