UFO stands for "Unidentified Flying Object" which is generally taken as a term from which one begins research. A UFO could be anything. A plane, a bird, a meteor, alien space craft, alien drone, anything. UAP stand for "Unidentified Aerial Phenomenon"... this means an investigation has already taken place and stuff like planes, birds and meteors, or balls of lightning etc. have ALL BEEN DISQUALIFIED AS PLAUSIBLE EXPLANATIONS.
As per a freedom of information request by To The Stars Academy Of Arts & Sciences, the US Department of Defense at the Pentagon has released THREE videos (which are also available to regular media through a Freedom of Information Act) with objects they believe to be UAPs and not UFOs, i.e. natural phenomenon and known technologies have been discarded as an explanation by the military.
Here is the first UAP (UFO) video from 2004 (These first two videos can also be viewed at the NY Times article, Glowing Auras and 'Black Money': The Pentagon's Mysterious U.F.O. Program)
Official DoD Video from Stars Academy: Gimbal (2004): The First Official UAP Footage from the USG for Public Release
Stars Academy Analysis: At 0:11, it is noted that “They are all going against the wind. The wind is 120 knots (138 mph) out of the west.” We can see that the speed and altitude of the object is unusual for any drone-type aircraft. On that information alone, the likelihood of an entire fleet of drones capable of operating under this scenario is highly improbable and would require resources only few nations could afford.
In the midst of this exchange, the sensor is switched from “white-hot” to “black-hot.” The imaging of the object is now much clearer. It has a distinct shape: a distorted oval with small protrusions from the top and bottom. The object’s opaque aura is now also very distinct: a “cool” glow that extends about a body thickness around the entire object. There appears to be no observable flight surfaces or exhaust plume, nor any typical components usually associated with conventional aircraft.
“Look at that thing, dude.” The observer is clearly surprised at what is being seen.
At 0:24, the object makes a small, but very sharp, altitude change, possibly indicating it may be operating in a vacuum environment. Its direction and speed remain unchanged despite the continuous 120-knot headwind it is encountering.
“That’s not [unintelligible] is it?”
At 0:27, the object begins a series of distinct rotations and changes orientation by almost 100 degrees. Its orientation is now perpendicular to the horizontal plane despite the headwinds. This maneuver is executed in a manner that is inconsistent with current principles of aerodynamics, and possibly indicative of a vacuum environment. As the video concludes, the object's orientation and performance seem to defy current principals of physics to include atmospheric resistance and normal aerodynamic forces. During the orientation change, it also slows to a near stop, but does not change altitude. Read full analysis here.
The second one doesn't have much information.
Here is the second video from 2004;
Official DoD Video from Stars Academy: FLIR1 (2004): Official UAP Footage from the USG for Public Release
Stars Academy Analysis: At 1:14, the object suddenly and instantaneously accelerates to the left, out of view of the sensor at what appears to be unprecedented velocity without a sonic boom or other associated tell-tale signatures of a conventional craft. The acceleration is so high that the sensor cannot maintain track. This type of flight performance cannot be achieved by any known aircraft. Read full analysis here.
The third video is from 2015 and shows the amazement of the pilots which does indicate we are watching something amazing as far as speed is concerned (This video is also in USA Today: UFO encounter? New footage shows U.S. Navy pilots' apparent sighting of alien craft near East Coast );
Official DoD Video from Stars Academy: Go Fast (2015): Official USG Footage of UAP for Public Release
Read analysis here.