While we commonly refer to these instruments as "telescopes," they can also be described as an "optical tube on a mount." This highlights that the mount is just as crucial as the telescope itself. If the mount is unstable or too lightweight, your images will suffer as a result. Even the best telescope won't deliver quality images with an unstable or light mount, as it will cause images to bounce and blur while focusing.
The alt-azimuth mount is a basic telescope mount that moves in altitude and azimuth directions. The name derives from the two axes of motion.
Amateur astronomer John Dobson invented a type of alt-azimuth mount that now bears his name in the 1960s. The Dobsonian mount is inexpensive and always paired with a reflector by manufacturers. The tube's loose fit allows for easy portability, but these scopes can also be quite large. Any amateur telescope with a mirror larger than 16 inches is placed in a Dobsonian mount.
If the Earth were stationary, a non-motorized alt-azimuth mount would suffice. However, since our planet rotates, we need a different type of mount - the equatorial mount. Joseph von Fraunhofer, a German optician, invented it in the early 19th century to track the stars. By aligning one of the mount's axes parallel to the Earth's axis and moving it (with a weight-driven clock drive) at the same rate as our planet's spin, the telescope follows the stars as they move through the sky. Nowadays, many equatorial mounts come with a motor to move them.
The go-to mount is a new innovation in which motors are attached to both the altitude and azimuth axes. These motors connect to an onboard computer that finds and tracks your celestial target after a simple setup process.
This mount system is highly precise. Once it locates an object, it will follow it as it moves across the sky without the need for manual adjustments. Modern go-to scopes come with large databases containing thousands of objects.