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An altazimuth mount is a straightforward mounting configuration of a telescope, using a horizontal axle for adjusting its altitude, in turn, mounted on a vertical axle for adjusting its azimuth. The design can provide the means to view any portion of the visible sky. Such a telescope can be termed an altazimuth telescope.
The main alternative is the equatorial mount, which has an axle parallel to the Earth's axis of rotation, so a simple, constant velocity rotation allows it to track objects in the sky. Equatorial mount was once preferred, but being bulkier, makes a significant difference for large telescopes, and with the development of computer control, the coordinated adjustments necessary to track objects similarly using an altazimuth mount are easily handled.
Among the other types of mounts: a transit telescope uses just a horizontal axle, the azimuth fixed (typically oriented to north-south, with the telescope able to swing past the zenith); and the Southern African Large Telescope (SALT) and Hobby-Eberly Telescope (HET) use a mount with just a vertical axle, their altitude being fixed at 63°.