Need is something you must have to survive, stay healthy, or accomplish something important. Humans need food, water, shelter, and sleep to stay alive. A plant needs sunlight and water to grow. A car needs fuel to run.

The word helps us distinguish between what's essential and what we merely want. You need a winter coat when it's freezing outside, but you want a coat in your favorite color. You need to study for tomorrow's test, but you want to play video games instead. Understanding this difference helps you make decisions about how to spend your time and money.

Need works as both a noun and a verb. As a noun, it describes the thing itself: “Our greatest need right now is firewood.” As a verb, it describes requiring something: “We need to leave soon or we'll be late.”

When someone is in need, they lack something essential and require help. People sometimes say they need something when they really just want it badly, like “I need that new game!” But true needs are non-negotiable requirements. You can live without the game. You cannot live without water. That's the difference that matters.