A fax machine is a device that transmits documents over a telephone line. It scans a physical document, converts it into a digital signal, and sends it to another fax machine, which then prints a copy of the document. This technology was widely used in offices for sending contracts, forms, and other important papers quickly. Although the use of fax machines has declined with the rise of email and digital communication, they are still utilized in certain industries, such as healthcare and legal services, where signed documents are often required. Many businesses maintain fax machines for these specific needs.