Reflecting telescopes use a curved mirror or a set of such mirrors to focus light, and refracting telescopes use a system of lenses.
(Reflecting telescopes; use; a curved mirror or a set of such mirrors; to focus light) (refracting telescopes; use; a system of lenses)
Reflecting telescopes refracting telescopes
use use
a curved mirror or a set of such mirrors to focus light
a system of lenses