HUMANS - Humans are the dominant species on Aeruen.  They make up about 67% of the sentient population, being the fastest to reproduce.  They are very diverse with a variety of ethicities, languages, and cultures.

MECHANITES - Living humanoid machines.  They consist of several different ethnic groups, also called "subsets", and are native to the continent of Mechanor, which is divided by several soveriegn mechanite nations.  Their primary source of sustenance is a crystal called etheron.  Like humans, they have two genders, male and female, and sexually reproduce, though the term most commonly used is "creation sequence" or "replication sequence".  Mechanite offspring are normally similar in size and stature as human offspring and take about the same time to mature once removed from female-construction-bay section of her chassis, though the "gestation" phase is about two to three times that of  the human one. However, mechanite partners with sizable financial resources have been known to have an adult chassis pre-designed and constructed in which the offspring helix core ( the  source of sentience and concsiousness for any individual mechanite ) is then implanted.  Over a varying degree of time, the helix core will then proceed to analyze and reprocess the chassis circuitry to its needs.  This saves the female partner in the creation sequence a great deal of strain on her chassis and internal systems. 
Every hundred years or so, a mechanite has to Reprocess.  The mechanite shuts down for a day to anywhere up to ten years ( longest on record is 10 years and 3 days and 6 hours and 23 minutes and 51 seconds ) .  There is a chance ( the percentage of which has never been determined ) that the mechanite will not survive and his or her helix core will be permanently extinguished.  If the mechanite survives, more often than not he or she will be as they have always been, but sometimes they will look completely different from how they were before, sometimes even taking on a completely different personality and name.  In very rare cases, they will completely lose who they were previously, as though they were a newly constructed mechanite.
  Mechanites also have sleep mode which they can go in and out of at will to help conserve energy so that their self-repair systems can more adequetly function.  The mechanite self-repair system ( the mechanite equivalent to the human immune and healing systems ) is made up of microscopic machines called nanonites.

GENANOIDS - Genanoid is an acronym that stands for Genetically ENgineered humANOID.  Originally created by the genetics firm Tautan Industries, through the indroduction of Companion Models and the resulting "marriages", a sizable population has integrated itself into human societies.  But, because the general censes is that they are of a second class nature, being more reguarded as personal property than actual people, a growing number of them have began an underground "resistance", fighting for what they believe to be their very right to free will.