The "Distance Ladder" is a method used by astronomers to measure the distances to celestial objects. It relies on a series of techniques that build upon one another, starting with nearby objects and extending to more distant ones. The first steps often involve measuring distances to stars using parallax, which is the apparent shift in position when viewed from different angles. As astronomers move further out, they use standard candles, like Cepheid variables and Type Ia supernovae, whose intrinsic brightness is known. By comparing their known brightness to how bright they appear from Earth, astronomers can calculate their distance. This layered approach allows for accurate distance measurements across the universe.