There are currently 218 worlds of advanced intelligent races visiting Earth. They are all people the way we are people, but all as different from each other as we are from any of them.
They are each more advanced than we are yet, meaning further and longer evolved, and all in different directions. All have some of the same and some different natural and technological abilities, as well as some unique ones. They also possess the advanced benefits of shared knowledge, technologies and experience.
Each crew leader is here as the representative of his world, and each crew member is a true professional of his or her race. All of them are working together under the leadership of the most advanced of the races here.
All come from their own worlds nearby in our galaxy; most from our own third arm Orion, and just a few from nearby in our neighboring two arms. They use dimensional technologies to close vast distances, but even with these technologies, it takes so long to cross space between our worlds, that they have to set up here and stay to work. They each travel in their own large crafts in which they reside while here, parked outside our atmosphere, and use smaller shuttle crafts to approach the surface of our planet. They each return to their own homes to visit families and friends once or twice every year.
All advanced races visit their neighboring worlds.
"Demons are figments assigned a life form. Alien beings are life forms assigned our figments." -ES