The Children of the Vault are a group of fictional superhuman beings with Spanish codenames.
They are a team of supervillains opposed to the X-Men.
Their motives to attack both humans and mutants were not exactly clear to begin with, though it was known they held a grudge against Sabretooth.
Their motive is that they believe themselves to be the rightful species to inherit the planet, but must first wipe out everyone else.
They are not mutants, but beings evolved from a baseline human genome over a time period of 6,000 years.
Their society was raised in the hold of a ship where temporal acceleration technology was used to evolve individuals into superpowered beings, in a fashion similar to the creations of the Weapon Plus Program.
Due to genetic drift, they are a separate species from either baseline humans or mutant humans. (Marvel has many subspecies of humanity such as Eternals, Deviants, Mutants and the Neo).