Currently, mainstream researchers, like the government and scientists, use the term UAP, which stands for Unidentified Aerial Phenomenon or Unidentified Anomalous Phenomenon. Congress uses the latter. Most of us know the phrase UFO, meaning Unidentified Flying Objects. The U.S. Air Force created that acronym in 1952 at the beginning of their most extensive UFO investigation called Project Blue Book. Before that, the term “Flying saucers” was most common. However, it was too easy to make fun of and became synonymous with alien spacecraft.
Project Blue Book chief Edward Ruppelt wanted to bring seriousness to UFO investigations and emphasize that UFO meant Unidentified. We don’t know what they are; aliens are just one possibility.
Unfortunately, over the decades, UFO also became synonymous with alien spacecraft, despite researchers’ attempts to explain that we don’t know for certain UFOs are aliens. For that reason, the term UAP began being used by scienti5c and governmental agencies. The implication is that UFOs are too silly to investigate, but UAP are OK.