What is called “The mount” is the combination of both tripod legs or pier section and the mount head mechanism section that is comprised by 2 or more axes and has the purpose of allowing the movement of a telescope on a steady structure to frame or spot targets on the field of view of an eyepiece or camera.
The types of telescopes are basically 3, refractors, reflectors, and compound telescopes. Refractor telescopes are comprised by lenses, reflectors have mirrors and compound have both. There is no optical design that is perfect, so each design is more suitable for the specific astronomical subjects that are going to be observed, photographed, or studied.
These settings are recommended for long exposure photography of deep space objects. The same settings are suitable for Nightscapes or widefield shots of Milky way using lenses and stationary tripods or motorized mounts and pictures of nebulae and galaxies using telescopes and motorized mounts.