Humans are the most social of the sapient species, at least with respect to the other sapient species in the world — if they aren’t actively welcoming of others, they at least tolerate them most of the time. They are also one of the more adaptable of the sapient species: they can and will live pretty much anywhere that can support them.
From a game-mechanics perspective, these allow a Human character to use their Species as a free-invocation Aspect three times per session, but no more than one time each, for any of the following skills:
That is: a Human could invoke their Human Species as an Aspect for a +2 bonus to a roll, or a re-roll, for Empathy, then Deceive, then Contacts, but not Empathy after that first use.