Types of telescope
Astronomical telescopes and Terrestrial Telescopes are the two major types of telescopes based on what is observed.
Astronomical Telescope:

Astronomical telescopes are used to observe celestial objects such as stars, planets, galaxies, and satellites.
Astronomical telescope
Terrestrial Telescopes:

In an astronomical telescope, the image is inverted. As a result, it is not suitable for viewing objects on the Earth's surface. As a result, a terrestrial telescope is employed. It gives the impression of being upright.
Terrestrial telescopes
The main distinction between an astronomical and a terrestrial telescope is how the final image is erect in relation to the object.
Advantages of Telescopes:
• Elaborate view of the Galaxies, Planets, stars and other heavenly bodies is possible.
• Camera can be attached for taking photographs of celestial objects.
• Telescope can be viewed even with the low intensity of light.
Disadvantages of Telescopes:

• Frequent maintenances needed.
• It is not an easily portable one.