Ash is the soft, powdery substance that remains after something burns. When you burn wood in a fireplace, what's left behind is ash: a fine gray or white powder that crumbles at your touch. The same thing happens with paper, leaves, or many other things that burn.

Ash forms because fire consumes most of a material's substance, leaving only minerals and other materials that can't burn. If you've ever watched a campfire die down, you've seen how solid logs transform into glowing embers and finally collapse into a pile of ash. Volcanic ash is different, though: when a volcano erupts, it shoots out tiny pieces of rock and glass that have been shattered by intense heat and pressure.

People have found uses for ash throughout history. Wood ash contains nutrients that help plants grow, so gardeners sometimes sprinkle it on their soil. Ancient peoples made soap by mixing ash with animal fat. The word ashen describes something pale gray, like someone's face when they're frightened or ill: “Her face turned ashen when she heard the bad news.”

The phrase rise from the ashes means to recover from complete destruction, inspired by the mythical phoenix that burned up and was reborn from its own ashes.