Short form of
Jackson. It appeared in the video game
Mortal Kombat II in 1993. It first registered as a given name in the United States in 1995 (when it was used only five times) but steadily grew in popularity for two decades, probably inspired by similar names like
Max and
Dax and helped by a character of this name on the American television series
Sons of Anarchy (2008-2014).