Cavalry refers to a military unit that fights on horseback. Historically, cavalry units were essential for their speed and mobility, allowing them to outmaneuver infantry and engage in quick attacks. They played a significant role in battles from ancient times through the 19th century, often serving as scouts or flanking forces. With advancements in technology, such as the introduction of firearms and mechanized vehicles, the traditional role of cavalry has diminished. Today, modern cavalry units may use armored vehicles instead of horses, but they still focus on rapid movement and reconnaissance, adapting to contemporary warfare needs.