Question

What are the advantages of parallax?

Answer 1

If you look at something from two different, well-defined points, you may get an idea of distance.

Explanation:

That's one reason we have two eyes. Because our brain 'knows' the position of both eyes, we can see how far something is, and whether it's moving away or toward us.

The greater the distance between our "eyes", the better we can calculate the distance.

By putting our "eyes" at the extreme points in the Earth's orbit, we may calculate the distance to nearby stars quite accurately.