A pocket watch is a timekeeping device designed to be carried in a pocket, typically attached to a chain. Unlike wristwatches, pocket watches are larger and often feature intricate designs. They were popular from the 16th century until the early 20th century, serving as a status symbol and a practical tool for keeping time. Most pocket watches have a round case and a glass cover to protect the dial. They can be wound manually or have automatic mechanisms. Famous brands like Patek Philippe and Waltham are known for their craftsmanship, making pocket watches collectible items today.