A telescope is an optical instrument that uses lenses or mirrors and other optical devices to observe distant objects.  It uses the light refracted through the lens or reflected by the concave mirror to make it into a small hole and converge to image,  and then through a magnifying eyepiece and be seen, also known as the "thousand mile mirror".     The first function of a telescope is to magnify the Angle of distant objects so that the human eye can see details at smaller angular distances.  The second function of the telescope is to beam light collected by the objective lens, much thicker than the diameter of the pupil (up to 8mm),  into the human eye, allowing the observer to see faint objects that would otherwise be invisible. In 1608, Hans Liebosch,  a Dutch optician, accidentally discovered that he could see distant objects with two lenses, and was inspired to build the first telescope in human history.  In 1609, Galileo Galilei...
 It can be held and observed whenever you want. A small telescope allows you to see something more than the naked eye - lunar craters, some details of the other planets (Jupiter's cloud band, Saturn's rings, polar cap of Mars, Venus phase), binary (some of them, like Cygnus, is a beautiful thing), star clusters, nebulae, if lucky, there are other galaxies. Keep in mind that what you see in a telescope won't be as spectacular as what you see in an astronomy journal. "Is a nice aperture, and the telescope is still compact enough to be used often enough to take you anywhere you want to go. It's also fairly cheap. A computer model like the one you think of makes it easy to find targets even in light-polluted urban skies, but the best part is that it helps you track targets, compensating for the Earth's rotation, so you spend less time controlling and more time looking. If you have no experience with telescopes, Telescope for Beginners,I recommend checking out astro...