Mechanical or an Automatic Watch
Mechanical watches need to be wound by hand. The energy of the mechanical watch is driven by a mainspring. Automatic watches are mechanical watches that do not need to be wound by the wearer. The mainspring is wound when the wrist of the wearer is moved. The energy of the automatic watch is driven by a rotor.
Mechanical watches use a mechanism called the clockwork mechanism. The wearer has to wind a mainspring by hand. The energy is transmitted through gears and energizes a weighted wheel called the balance wheel. The balance wheel constantly swings back and forth. The wheels of the watch move forward after being released by a device called the escapement that makes a ticking sound and moves the hands of the watch.
Automatic watches do not need winding by hand. They are self-winding watches. The movement of the body gives power to the rotor. A swinging weight or rotor turns on a pivot. The winding mechanism is ratcheted. In some watches, the weight oscillates in one direction while in others the mainspring is wound when the weight moves clockwise and anticlockwise (see Maserati watch for example).
Mechanical watches are lightweight and thin. This is because it does not have a weighted motor. These watches do not need batteries and are environmentally friendly. Regularly wound mechanical watches can run for hours. They are durable and may not need repairs for several years.
Automatic watches wind automatically when the hand is moved and no effort to wind the watch is required. They do not need batteries. Maintenance is easy. Automatic watches store power for a very long time. Some watches store power for over a week.
Frequent winding is required to make mechanical watches work. They need regular maintenance. They are sensitive watches and stop or malfunction if the mechanism is exposed to dust, water-logging, dust, magnets or, shocks. They are best used as dress watches. Mechanical watches are costlier than other types of watches. Its accuracy is not perfect and needs to be tuned every few years.
Automatic watches should be worn daily. A winder needs to be installed if the watch is not used daily. Automatic watches are expensive. They also lose accuracy quickly and need regular tuning. The weight is placed on a pivot and this mechanism makes the watches bulky.
Automatic and mechanical watches have their advantages and disadvantages. Mechanical watches make excellent occasion-wear watches while automatic watches are meant for daily wear.