What is the difference between an equatorial mounted telescope and an Altazimuth mounted telescope?
A mount is said to be “equatorial” if one of its axes can be made parallel to the Earth’s axis of rotation (called the Celestial Pole). This is essential if you want to track an object over a long period of time as it moves across the sky. With an equatorial mount the motion of the sky can be cancelled out by simply turning its axis at the same rate as the Earth’s rotation, but in the opposite direction. Equatorial mounts are necessary for long exposure astrophotography and for using setting circles to locate objects. Altazimuth (short for Altitude/Azimuth) mounts are the simplest type of mount. This type of mount moves in two directions, altitude (up and down) and azimuth (side-to-side). Due to their ease of use, Altazimuth mounts are suited both for terrestrial viewing as well as astronomical observing.
