A Countdown Timer is a device or software application that counts down from a specified time to zero. It is commonly used in various settings, such as cooking, sports, and project management, to help individuals keep track of time remaining for a specific task or event. These timers can be digital or analog and often feature alarms or notifications to signal when the time is up. Many smartphones and computers come with built-in countdown timer functions, making it easy for users to set and monitor time limits for activities like exercise, meetings, or tests.