Trousers, slacks, or pants are an item of clothing that might have originated in Central Asia, worn from the waist to the ankles, covering both legs separately.
In the United Kingdom, the word pants generally means underwear and not trousers. Shorts are similar to trousers, but with legs that come down only to around the area of the knee, higher or lower depending on the style of the garment. To distinguish them from shorts, trousers may be called "long trousers" in certain contexts such as school uniform, where tailored shorts may be called "short trousers" in the UK.
The oldest known trousers were found at the Yanghai cemetery in Turpan, Sinkiang, in present-day western China, it's been dated to the period between the 10th and the 13th centuries BC. Made of wool, the trousers had straight legs and wide crotches and were likely made for horseback riding.
In most of Europe, trousers have been worn since ancient times and throughout the Medieval period, becoming the most common form of lower-body clothing for adult males in the modern world. Breeches were worn instead of trousers in early modern Europe by some men in higher classes of society.