Fax services allow individuals and businesses to send and receive documents electronically over telephone lines. This process involves scanning a physical document and transmitting it to a fax machine or a digital fax service, which then prints the document on the recipient's end. Fax services are commonly used for legal, medical, and business communications where signed documents are required. Many modern fax services operate online, enabling users to send and receive faxes via email or web applications without needing a physical fax machine. These services often provide features like secure transmission, document storage, and integration with other software, making them convenient for users who need to manage documents efficiently.