Posture is the way you hold your body when sitting, standing, or moving. When your teacher reminds you to sit up straight at your desk instead of slouching, she's talking about your posture. Good posture means your spine is aligned naturally, your shoulders are back, and your head sits balanced on top of your neck, like stacking blocks carefully so they don't topple over.

Posture affects how well your body works. When you maintain good posture, your muscles work efficiently and you breathe more easily. Slumping forward while reading or gaming might feel comfortable at first, but over time it can make your back and neck tired and sore. Athletes pay close attention to posture because the right positioning helps them run faster, throw farther, or balance better.

The word can also describe an attitude or position someone takes on an issue. When a country adopts a defensive posture, it's positioning itself to protect against threats. When someone takes an aggressive posture in an argument, they're approaching it ready for conflict. In this sense, your posture shows others how you're positioning yourself, whether physically or in your approach to a situation.