The 12-hour clock is a timekeeping system that divides the day into two 12-hour periods. The first period runs from midnight to noon, labeled as AM, while the second period runs from noon to midnight, labeled as PM. Each hour is numbered from 1 to 12, and the cycle repeats every 12 hours. In this system, the hours are often displayed on analog clocks with a circular face and two hands. The shorter hand indicates the hour, while the longer hand shows the minutes. The 12-hour clock is commonly used in everyday life, especially in countries like the United States and Canada.