The cosmic distance ladder is a series of methods used by astronomers to measure distances in the universe. Each step relies on different techniques, starting with nearby objects and gradually extending to more distant ones. For example, the distance to the Moon can be measured using radar, while the distance to nearby stars is determined using parallax. As astronomers move further out, they use standard candles like Cepheid variables and Type Ia supernovae to estimate distances. These methods build on one another, creating a reliable framework for understanding the vast scales of the universe, from our solar system to distant galaxies.