Soon means in a short time from now, or before long. If your mom says dinner will be ready soon, she means it won't take very long, maybe ten or fifteen minutes. If a friend says they'll arrive soon, they're already on their way.

The tricky thing about soon is that it's flexible. What counts as “soon” depends on the situation. When you're waiting for recess, five minutes might not feel very soon at all. But when you're talking about a space mission to Mars, launching “soon” might mean in two or three years. When a doctor says a broken bone will heal soon, that might mean six weeks, which doesn't feel soon when you're itching under your cast.

People sometimes use soon when they don't want to commit to an exact time. A parent might say “we'll go to the park soon” without specifying Saturday or Sunday. This can be frustrating when you're eager for something to happen, because soon leaves room for interpretation.

The phrase sooner or later means eventually, meaning that something will definitely happen even if you don't know exactly when. And if someone asks you to do something as soon as possible, they mean they want you to do it at the earliest moment you can.