Transmission need is a term used to describe the various components necessary for the successful operation of a transmission system. FLUID, gearoil, modem, and FAX are all components that are necessary for a transmission system to function properly. FLUID is a liquid or gas that is used to lubricate and cool the moving parts of a transmission system. Gearoil is a type of oil specifically designed to lubricate the gears in a transmission system. Modem is a device that allows two computers to communicate with each other over a telephone line. Finally, FAX is a technology that allows documents to be sent electronically from one location to another. All of these components are essential for a transmission system to work properly.