Humans (Homo sapiens), also known as Terrans, are a warp capable humanoid species from the Alpha Quadrant. This species originated from planet Earth in the Sol system. Humans are one of two known spacefaring intelligent species to have originated from Earth; the other being the Voth that now live in Delta Quadrant.
As the Latin word for their homeworld was "Terra", Humans were sometimes referred to as "Terrans". (This usage was consistent in the mirror universe.) Occasionally the term Terran was used to distinguish Humans living on Earth from those resident on colonies on other planets and moons. Some people used the adjective "Terran" to refer to subjects or institutions associated with Humanity (Terran cuisine, Terran literature, Terran art, etc.).
A founding member of the United Federation of Planets, Humans of Earth became warp-capable in 2063, which was the same year they experienced first official contact with an alien species, the Vulcans. The first warp-drive was engaged on April 5th of that year by Zefram Cochrane.