A wristwatch is a small clock that straps around your wrist so you can check the time anywhere you go. Before wristwatches became common in the early 1900s, people carried pocket watches on chains, which meant fumbling through their pockets every time they wanted to know the time.

Wristwatches became popular during World War I when soldiers needed to check the time quickly during combat without digging through their uniforms. After the war, many people started wearing them because they were so practical. Today, wristwatches range from simple timepieces that just show hours and minutes to complex instruments that can track your heartbeat, count your steps, or even make phone calls.

Some wristwatches are mechanical, powered by tiny gears and springs you wind up, while others are digital, running on batteries and showing the time with electronic numbers. Mechanical watches are marvels of miniature engineering: hundreds of microscopic parts working together to measure time. Many people treasure mechanical wristwatches as works of craftsmanship, even though digital watches are often more accurate.