A countdown is a sequence of backward counting to indicate the time remaining before an event occurs. It is commonly used in various contexts, such as launching rockets, starting races, or celebrating New Year's Eve. The countdown helps build anticipation and excitement as the moment approaches. In technology, countdowns are often displayed on screens or devices, showing the time left in seconds or minutes. They can also be found in apps and games, where players may have a limited time to complete tasks. Overall, countdowns serve as a clear and engaging way to mark the passage of time leading up to significant events.