I can't quite grasp the simple version of how the Cepheid method uses the parallax method to measure the distance to distant galaxies.
What I know is that Cepheids exhibit a period vs luminosity relationship that can be measured for nearby galaxies. Using the actual luminosity (obtained from measuring the period) and the apparent luminosity (measured from Earth) we can then calculate the distance of the galaxy containing the Cepheid from us.
However, I don't know how the parallax method comes in to play?
In addition, in one section of my notes, the professor had said that the Cepheid method only works for nearby galaxies, yet in another section, it is said that the combination of the parallax method and the period vs. luminosity relationship allows for measurement of the distance to "more distant" galaxies.