Significance means importance or meaningfulness. When something has significance, it matters in a noticeable or lasting way. A teacher might tell you that a historical event had great significance because it changed how people lived or thought. A scientific discovery has significance when it helps us understand something important about the world.

The word often appears when people are trying to explain why something matters, beyond describing what happened. The significance of the first moon landing was that it showed humans could achieve seemingly impossible goals through science, engineering, and determination. When you analyze a story in English class, you might discuss the significance of a character's decision, meaning why that choice mattered to the plot or what it revealed about the character.

Something can also be significant to you personally without being important to everyone. A worn baseball glove might have significance because your grandfather gave it to you, even though it wouldn't mean anything special to a stranger. The opposite of significant is insignificant: small, unimportant, or not worth noticing.

When scientists talk about statistical significance, they mean their results probably didn't happen by random chance. The pattern they found is real and meaningful enough to pay attention to.