If the objective is a lens, the telescope is said to be a refractor because the lens focuses the light by the process of refraction.
(the objective; is; a lens) (the telescope; is said; ) (the telescope; to be; a refractor) (the lens; focuses; the light; by the process of refraction)
the objective the telescope the telescope the lens
is is said to be focuses
a lens
a refractor
the light by the process of refraction