telescopes collect light, and magnify.

basically. that means you can see things "closer up" and fainter things are brighter, or things that are invisible to the unaided eye, become visible.

the details on the moon are greatly enhanced with a scope.

the planets, which look like pinpoints of light with the eye, can be resolved into spherical "discs" with a telescope!

the stars, are far too distant to be resolved into their discs. but can be brighter, and you can see fainter ones.

because of magnification, your field of view will get smaller… think of looking at a mountain from 1 mile away instead of 100 miles away. it's bigger, you can see more details, etc… but the percentage o that mountain that you can see within the size of say, a sheet of paper held at arms length, is much less.

A telescope does two act simultenously first it increases the optical angle of the object hence size of the celestial body appears to be big and detailed.Secondly our eyes can see only those objects which have light intensity more than a certain limit,if the object have intensity less than that human eye wont respond to the image formed on the retina.While increasing the optical angle the light intensity of the object is reduced this so higher is the diameter of the objective lens of the telescope more will be the quantity of light entering telescope which increses the quality of image.so higher is the magnification and diameter if objective lens of telescope we can see depth details of stars and other celestial bodies

Why don't you see for yourself?