Hour - a unit of time equal to 60 minutesMinute - a unit of time equal to 60 secondsClock - a device used to measure and display timeTime - a measure of the duration of eventsAnalog - a type of clock that displays time using handsDigital - a type of clock that displays time using numbersHands - the moving parts on a clock that point to the timeNumerals - the symbols or figures used to represent numbers on a clockTwelve-hour clock - a clock that uses a system of 12 hours, designated as a.m. or p.m.Twenty-four hour clock - a clock that uses a system of 24 hours, also known as military time.