Telescopes use lenses or mirrors to make distant objects appear larger and closer. Refracting telescopes use lenses to bend and focus light, while reflecting telescopes use curved mirrors. Catadioptric telescopes combine mirrors and lenses. Telescopes are used to observe objects that are too far away to see clearly with the naked eye, without needing to physically get closer. The magnification of a telescope depends on the focal lengths of its objective lens and eyepiece. Larger aperture telescopes can capture more light but have limitations like chromatic aberration.