Horizon

The apparent line that separates earth from sky. Learn more on Wikipedia.

Hyperfocal Distance

The closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp. When the lens is focused at this distance, all objects at distances from half of the hyperfocal distance out to infinity will be acceptably sharp. Learn more on Wikipedia.

Near Limit

It is situated at half the hyperfocal distance. If we focus at the hyperfocal distance, we'll get sharpness from the Hyperfocal Near Limit to infinity.