A watch is device to view the time. The watch is one of the oldest human developments its organization in time.

The first clock is a sundial, the sundial, which measures the time of day by the direction of shadows by the sun, its showing the timing only daytime. Sundials can show local solar time with reasonable accuracy, and sundials continued to be used to monitor the performance of clocks until the modern era.

Later years saw the rise of automated water watch in Arabia , China , India , and Korea . The first clocks developed from 13th century in Europe , but various mentions in records reveal some of the early history of the clock. Clockmakers building smaller clocks was a technical challenge, as was improving accuracy and reliability. Clocks could be impressive showpieces to demonstrate skilled craftsmanship, or less expensive, mass-produced items for domestic use. Clocks were developed during the 15th century, and this gave the clockmakers many new problems to solve, such as how to compensate for the varying power supplied as the spring unwound. The first hand watch developed Almanus Manuscript of Brother Paul in 1475.

Today many clocks are present in marketplace its main type of clock is following:

• Analog clock : Analog clocks show time using angles. The analog clock using fix numerical dial and running heads. It usually has a circular range of 12 hours and every hour 60 minute present.
• Digital clock : Digital clocks display a numeric image of time. The two types are showing the time. 24 hour information has hours raining 00 to 23 and 12 hour notation with AM/PM sign. 12 AM follow by 1AM to 11AM and 12 PM follow by 1 PM to 11PM (AM/MP unit using mostly in US).
• Auditory clocks : Auditory clocks present the time as sounds. The sound is either speaks natural words.

The biggest clock in the world is The massive clock on St. Stephen's Tower, London . (Big Ben). Its total size is 5 foot 4 inch (1.63 m).The hour hand length is 9 feet and minute hand length is 14 feet (4.3 m).

Watch is vary important part of human life. Its needed item in every nun.