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what is the difference between a newtonian and a galilean telescope?

Galilean Telescope or Refracting Telescope uses a convergent (plano-convex or bi-convex) objective lens and a divergent (plano-concave or bi-concave) eyepiece lens. Galilean telescopes produce upright images.Galileo’s best telescope magnified objects about 30 times. Because of flaws in its design, such as the shape of the lens and the narrow field of view, the images were blurry and distorted. Despite these flaws, the telescope was still good enough for Galileo to explore the sky. The Galilean telescope could view the phases of Venus, and was able to see craters on the Moon and four moons orbiting Jupiter.  

The Newtonian telescope is a type of reflecting telescope invented by the British scientist Sir Isaac Newton using a concave primary mirror and a flat diagonal secondary mirror. Newton’s first reflecting telescope was completed in 1668 and is the earliest known functional reflecting telescope. The Newtonian telescope's simple design makes them very popular with amateur telescope makers.Newtonian telescopes are usually less expensive for any given aperture than comparable quality telescopes of other types. And a short focal ratio can be more easily obtained, leading to wider field of view.  

The eyepiece is located at the top end of the telescope. Combined with short f-ratios this can allow for a much more compact mounting system, reducing cost and adding to portability, Which was not in the Case of Galilean Telescope.

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