Traditionally manufactured watches have many internal components that are linked and some of these parts need to be in constant motion to ensure the proper functioning of the clock. The power or the energy that is needed for these parts to be in perpetual motion, used to be provided in the olden day watches with the help of a metal coil. This coil or spring type mechanism would be wound tightly and its natural tendency to slowly set itself right would provide the necessary energy for the other parts to continue their movements. After a while, this coil will lose its stored energy and would have to be rewound again. These types of watches were called manual re-wind watches. These watches need to be rewound on a daily basis otherwise, they would stop working.