Final answer:
A fax machine transmits hard copy written messages. It operates on principles similar to xerography used in copy machines and communicates over phone lines or microwaves.
Step-by-step explanation:
The piece of equipment that allows you to transmit hard copy written messages is a fax machine. To understand how a fax machine operates, it is helpful to know about the process called xerography, which is used in most copy machines. Xerography is an electrostatic process, stemming from the Greek words xeros for 'dry' and graphos for 'writing'. The heart of the xerography process is the electric charge that creates an image on a drum, which is then transferred onto paper. While xerography refers to copying, fax machines work on similar principles but include scanning a document and transmitting that information via microwaves or phone lines to another fax machine that prints out the original document.
Earlier forms of message transmission included the telegraph, which revolutionized communication by allowing almost instant messaging using Morse Code over long distances, setting the stage for modern communication technologies including fax machines. Modern paper and writing devices, which are still prevalent today, often work alongside such communication technologies.