Darkness is the absence of light. When the sun sets and night falls, darkness spreads across the sky. In a room with no windows and the lights turned off, you experience complete darkness, where you can't see your hand in front of your face.

Darkness comes in degrees. Twilight is the soft darkness that arrives just after sunset, when you can still make out shapes and colors. Pitch darkness means total blackness, like deep inside a cave where no light reaches at all. Your eyes actually adjust to darkness over time, which is why a dark room seems less dark after you've been in it for a few minutes.

People use darkness metaphorically to describe sad, frightening, or evil things. A dark mood means feeling gloomy or unhappy. A dark period in history refers to a time of suffering or cruelty. When someone talks about the darkness in a scary story, they often mean something mysterious or threatening, not just the absence of light.

Darkness makes things harder to see and understand, which is why we associate it with the unknown and sometimes with fear. But darkness also brings rest: most creatures, including humans, sleep when darkness falls, using night as a time to recover their energy for the next day.