The Hubble Telescope was named after Edwin Hubble, an astronomer in the 1920's who discovered many important foundations for astronomers today. The telescope, which weighs 25,000 pounds, has been in orbit around Earth for over 20 years and has had several missions to repair it. It is one of the only in-space telescopes and can take clear pictures billions of light years away - a near unfathomable distance. The telescope was sent up in 1990 and since then has sent numerous images that have been claimed as astronomic classics - pictures easily recognizable in any science textbook. Its purpose was to see what was beyond on our galaxy, and it accomplished that and beyond- we now know how many billions and trillions of galaxies are out there.
It's 7 feet 10 inches in diameter and has 48 square feet of collecting area. The focal length is 189 feet. It has an infrared camera/spectrometer, a nearly failed optical survey camera, and several other types of spectrometers and cameras.
It functions with a mirror, classifying it as a "reflector" telescope (optical).
The telescope itself:
Some stunning images taken by Hubble:
The Carina nebula, a birthplace of galaxies, sometimes referred to as a "nursery".
An gigantic cluster of galaxies located over 2 billion light years away.
Neat Video to Watch:
All information was found on the official NASA Hubble site. (Wikipedia was used for the dimensions, which I assume were found on the official site as well).