Ram-jet propulsion refers to a type of engine system that is often used in supersonic aircraft. It involves the propulsion of an aircraft through the use of forward thrust, rather than the use of traditional wings and lift. Some synonyms for this type of propulsion system may include jet propulsion, combustion propulsion, or even scramjet propulsion (which uses supersonic combustion). Other terms that are used to describe similar systems include afterburners, turbojets, and pulsejets. Regardless of the term used, ram-jet propulsion is a highly effective way to accelerate an aircraft to incredibly high speeds, making it invaluable for military and industrial applications.