Distances to stars, in astronomy, is based on how long it took the light to get here.
Since what we see is the light, then we see the star as it was, when the light left there.
Compared to distances in the universe, light is "slow". For example, the light from the pole star (Polaris, in the constellation of the small bear) takes roughly 400 years to get here. Therefore, when we look at that star "now", we see it as it was 400 years ago.
And we say its distance is "400 light-years".
Using that system, our Sun is (on average) 499 "light-seconds" away; we see it as it was 8m19s ago. In January it is a bit closer, and in July it is a bit further away.
If you observe the sky from a very dark site, you can see a blotch that we call the Andromeda galaxy. It is two-and-a-half million light-years away. We see it (and all the stars it contains) as it was 2.5 million years ago. People doing celestial mechanics (calculating the movement of objects) will use the galaxy's proper motion (and our own Galaxy's motion) into account to calculate the present position.
However, in astronomy we don't bother. If you see a star that suddenly flared up last night, you simply say "it flared up last night". You don't bother trying to work the time backwards to (let's say) whatever date it was, 400 years ago, when the star really flared up.