Meade DS-2090 Instruction Manual page 2

Refracting Telescopes use a large objective lens as their primary
light-collecting element. Meade refractors, in all models and apertures,
include achromatic (2-element) objective lenses in order to reduce or
virtually eliminate the false color (chromatic aberration) that results in
the telescopic image when light passes through a lens.
Reflecting Telescopes use a concave primary mirror to collect light
and form an image. In the Newtonian type of reflector, light is reflected
by a small, flat secondary mirror to the side of the main tube for
observation of the image.
Eyepiece
F
Refracting Telescope
In the refracting telescope, light is collected by a 2-element objective
lens and brought to a focus at F.
Concave
Mirror
Reflecting Telescope
In contrast, the reflecting telescope uses a concave mirror for this
purpose.
2-Element
Objective Lens
Secondary
Mirror
F
Eyepiece