When you are stargazing, the farthest you can see along the ground in any direction is called your celestial horizon.
Just as the Sun rises over the horizon, so do all stars appear to rise and set over your celestial horizon.
On a map, your celestial horizon corresponds to Earth’s horizon around you, but when you are actually outside looking at the sky there are buildings, fences, trees, and many other objects that get in your line of vision.
The circle around you where the sky and ground meet is called your celestial horizon.
Everyone’s celestial horizon is different, it depends on where you are standing.