Humans are the dominant and most advanced species of the Milky Way and many other galaxies within the Virgo Supercluster.
Humans originated on the planet Earth, humans are an intelligent bipedal hominid. They have four limbs, two arms, and two legs, and are advanced tool users. They rose to become the dominant species of the planet many millennia ago, spreading out from the African continent to inhabit the rest of the world. Their arms have five digits called fingers which is useful for eating and fashioning tools.
Thanks to advancement in medicine, the average lifespan of a human could now be considered practically immortal. The two main causes of human death are accidents and murders.
Humans have come far and then they started their colonization of the universe starting with Luna. For hundreds of years, they have colonized and terraformed planets in the Sol System (except for the gas giants because they have no solid surface), and many other star systems. Then they went to other galaxies and colonized them.
However, because of their colonization of many different planets, the form humans now take have altered wildly, so much so that there are some humans who have altered their DNA so that they can live in certain alien environments. As such, Human is now a much broader statement. Most now prefer to be called by alternate names. For example, Humans from Earth prefer to be called Terrans, those from Mars Martians, those from Terranova Novans, etc. Pretty much gods.
Human culture is hard to pin down, considering the fact that humans inhabit most of the Milky Way as well as many other galaxies. There is no central government but a loose organization of all the worlds known as simply the Confederacy of Humanity, but the Sol System is held in high regard to nearly every human as it is the birthplace of humanity. Every human across the galaxy has visited Earth at least once in their life. Each human world is self governed and some, like the Amish Homeworld, is more or less left alone.
The Confederacy has no official army as they have not been in many conflicts with any other alien race, but some more militaristic worlds have a fleet of battleships they keep on standby. In times of war, these battleships can be conscripted into the Confederate Navy, one of, if not the most, powerful fleets in the local galactic area.