Future Trunks is a Saiyan-Earthling hybrid and the son of an alternate future Vegeta and Bulma. The timeline had been drastically altered by Future Trunks’ and Cell’s trips to the past by the time Present Trunks was born. As a result, the two Trunks had very different lives (as opposed to those who lived before the Time Machines arrived, who lived exactly the same lives as their counterparts until the point at which the two timelines diverge, three years before the androids arrived).
Trunks is a well-mannered, serious, and cautious character from an alternate timeline in which Future Androids 17 and 18 murdered the Dragon Team and caused an apocalyptic anarchy on Earth. Trunks is trained as a teenager by Future Gohan and becomes a gifted fighter, swordsman, and Super Saiyan, all of which help him greatly in his battle against the Androids after travelling back in time to save his own future.