[Units & Dimensions] Measuring Distances Using Parallax

Am I right in thinking that in this example I've drawn here, while measuring shift in position of the star X (which I've denoted here by 2θ) using the photographs we click 6 months apart, we are able to take the far-away stars as stationary points of references which is where "parallax" is coming into play? I'm sorry if there are any inaccuracies in the example or what I've said, please point them out to me. IDK astrophysics and stuff, and only wanted to be clear about the parallax stuff for now.