Although the vast majority of Swiss watches sold are powered by a quartz movement, watch afficionados prefer mechanical movements because of their unique blend of art, engineering, and human ingenuity. There are two major variants.
An automatic mechanical, usually just called an automatic, requires no winding because of the rotor, which winds the mainspring every time you move.
A manual watch, also referred to as a hand-wound mechanical watch, slowly unwinds the mainspring in an even motion releasing energy that powers the timepiece over a period of time.
Most mechanical movements are accurate within a few seconds each day and have reserve power when not worn that typically lasts around 40-50 hours.