The James Webb Space Telescope is the largest and most powerful space telescope ever built, and its images regularly make headlines. But those images can be misleading if you do not know what you are looking at: Webb does not see the universe the way your eyes do.

Webb sees infrared light, which is light with wavelengths longer than visible light. We feel infrared as heat, and it has a useful property: it passes through dust clouds that block visible light. That means Webb can peer inside star-forming regions that look dark and empty to ordinary telescopes.

Because the universe is expanding, light from the most distant galaxies has been stretched into infrared by the time it reaches us. This is why Webb is the right tool for studying the early universe: it can detect galaxies whose light left them when the cosmos was very young.

Webb's most famous targets include early galaxies, glowing nebulae, star clusters, and the atmospheres of exoplanets. When a planet passes in front of its star, a tiny amount of starlight filters through its atmosphere, and Webb can read the chemical fingerprints in that light.

Webb also studies objects closer to home, including planets, moons, asteroids, and comets in our own solar system. Its infrared vision reveals temperatures and compositions that visible-light telescopes miss.

What Webb cannot do is just as important. It cannot take a sharp photograph of an exoplanet's surface, because those planets are far too small and faint next to their stars. It cannot look at the Sun, because its sensitive instruments must stay extremely cold behind a tennis-court-sized sunshield.

The best way to enjoy Webb's work is to follow the official image releases and read the short explanations that come with them. Each image is a scientific measurement first and a picture second, and understanding that makes the view far more rewarding.