In astronomy, "standard candles" are objects with known brightness, allowing scientists to measure distances in the universe. By comparing their actual brightness to how bright they appear from Earth, astronomers can calculate how far away they are. Common examples of standard candles include certain types of supernovae and Cepheid variable stars. These objects are crucial for understanding the scale of the universe. For instance, using standard candles, researchers can determine the distance to galaxies and study the expansion of the universe. This helps us learn more about cosmic phenomena and the overall structure of the cosmological landscape.