Turning them off makes the program run a little bit faster. You can also select the patterns by which the constellations are connected. They are intended to be more logical than the standard ones, even if they omit some stars. Displaying fewer stars makes the program run faster. They are very similar to the Earth-based coordinates of longitude and latitude.
Declination is very much like latitude on the Earth.
The word Celestial is used to distinguish between, for example, the North Pole in the sky and the North Pole on the Earth. The Celestial Poles lie directly above the Poles on the Earth, so if you were at the North Pole, the North Celestial Pole would be directly overhead. Keep in mind that the places on the so-called Celestial Sphere are directions not positions . Two stars that appear next to each other on the sky may actually be very far apart in reality if one is much further away from the other. Right Ascension is similar to longitude on the Earth, however it is numbered differently.