it seems that the UFO is partly alive, ie the pilot and the flying machine become one.
the UFO receives coordinates of space, time and consciousness, that is, the point of reality experienced by those who must be kidnapped (for example).
these coordinates are collected by probes, often of military origin (military and aliens work together for a common project).
when the UFO has the destination data it starts to vibrate, it becomes light and appears at the point of arrival instantly, just having the correct data. the whole thing works at low energy, trivial electricity probably and the light seems to be the basis for this teleportation.
it is as if the UFO perceives the destination and its structure becomes compatible to exist only in the destination.
There are scientific theories that explain this phenomenon, like Bohm's holographic universe. where there are no distances and time does not exist, everything happens in a single moment.
if aliens know this fine reality of the universe they can go anywhere in an instant with technology because in reality nobody really moves, because the universe would be condensed into a small infinitesimal point.