Parallax is measurement via the Earth's orbit around the Sun, Sol. In six months from now, we will be on the other side of the orbit, and orbit that is 93,000,000 or so miles in radius. That makes the base of the triangle 186,000,000 miles in length. Therefore parallax comes from using that base and the triangle to the star and measuring how much it moves to our line of sight, notwithstanding proper motion of the star (is it moving closer to us or is it moving further away, measured by red shift which does involve the elements that make up the star and a spectrograph measurement, and also tells how hot the sun (star) may be by measuring the elements in the star - since stars start off by burning hydrogen the simplest element and the universe, until the star changes that to helium, and then has some heavier elements in it, all the way up the chemistry charts to iron.

That covers cepheid variables also because parallax can only be good out to a certain distance using the diameter of the Earth's orbit. But as satellites orbit and take better measurement the distance probably will be more accurate - in the future.