"Augments" is a colloquial term for people who were altered using early and enormously primitive bio-technology or genetic engineering.
There are actually numerous subtypes, factions, sources and generations of "Augments". the rise of Khan Noonian Singh and his cadre of "Supermen" threw the earth into a violent war with a death toll in the hundreds of millions.
Khan and his crew are the source of the Federations horror of genetic engineering and attemmpting to upgrade humans.
ST-OM: Star Trek is a "Retro" Sci-fi flavored Fantasy setting. It's about the human spirit and the human adventure of exploring and meeting "the Other".
Add any transhumanism or post humanism, and you have harder Science Fiction - but what's left doesn't taste like Trek to me.
the Augments, the Borg and others are okay as villains. But one of the core flavors that goes into trek is the underlying assumpption. Kirk, Picard and so on are exxceptional - but they're us. that's US going out there. You don't want to lose that.
More description of the Augements and their history coming up