A copier, also known as a photocopier, is a machine that makes duplicate copies of documents and images. It works by using light, heat, and chemical processes to transfer the original content onto paper. Copiers are commonly found in offices, schools, and print shops, where they help streamline the reproduction of important materials. Modern copiers often come with additional features, such as scanning, faxing, and printing capabilities. Many are multifunction devices that can handle various paper sizes and types, making them versatile tools for both personal and professional use. They play a crucial role in document management and communication in today's digital age.