A ruler is a simple tool used to measure length or draw straight lines. Typically made of wood, plastic, or metal, it usually has markings in centimeters and inches. Rulers are essential in classrooms, workshops, and homes, helping people create accurate drawings or measurements for various projects. In addition to their practical use, rulers can also be found in art and design. Artists often use them to ensure precision in their work, while architects rely on rulers to create detailed plans for buildings. Overall, rulers are versatile tools that play a crucial role in many fields, from education to construction.