Terragen

Terragen is anything or anyone whose ultimate origins can be traced back to planet Earth, but does not necessarily live there in the Orion's Arm universe. For beginners, Terragens constitute of humans, artificial or virtual intelligences, and uplifted or entirely novel organisms.

Human
Genomically-pure Homo sapiens sapiens, named baseline humans, are just one of the 36,000 human subspecies in Orion's Arm. The remaining subspecies have been created through genetic engineering and cybernetic enhancements, named near-baseline humans.

Some subspecies of nearbaselines include: In nearbaselines, radical improvements (supercentenarian life expectancies and the ability to regrow severed limbs) are few while subtle ones (increased symmetry, microgravity adaptations and producing more amino acids) are numerous.
 * Homo sapiens plebus (with at least 10,000 phenotypic races)
 * Homo sapiens lunensis
 * Homo sapiens mediaphilus
 * Homo sapiens pacificus
 * Homo sapiens proximacentaurensis
 * Homo sapiens novaterraensis
 * Homo sapiens quarkensis

In the case of the superiors or the Homo superior, this is not the case. Radical enhancements are the norm, and unlike nearbaselines, their creation has been extensively planned. Superiors need little sleep, have augmented senses, can survive water-freezing temperatures, can hold their breath for minutes and tolerate toxins much better than (near)baseline.

Nearbaselines number 15 quadrillion and superiors 1.2 quadrillion. With just 150 billion baselines, modified humans augment the original ones 108,000 to 1 in Orion's Arm.

Cyborg
Cyborg is any biont that cannot function properly without an integrated electronic device. As such, it is not a excluding label of sophonts, since for example, an intelligent African Grey Parrot could sport inorganic implants, thus being provolve and cyborg simultaneously. Indeed, the Encyclopedia Galactica emphatizes the diversity of hosts of cybernetic implants. There are some 6 quadrillion cyborgs.

Provolve
"Any species of subsapient or presapient animal, plant or other non-sophont biological organism, that has had its genotype modified and intelligence enhanced by whatever means to the level of sophonce, along with any genomic and/or bionic augmentations required for manipulation of objects, interfacing with tech, communications, and other necessities of civilized life."

- Encyclopedia Galactica on provolves.

In layman's terms, a provolve is an animal, plant or any other life that has been altered to possess human intelligence. It is what is known as "uplift" in other science fiction works. The term "provolve" is short for "proactive evolution". Novel, artificially created species and genomically-reconstructed ones can also be provolved.

With 6 quadrillion of such individuals, there are numerous provolve clades. Species that have been provolved include African grey parrots, albertosauruses, annelids, ants, cephalopods, chimpanzees, dogs, dolphins, elephants, geckos, gorillas, insects, kelp, meerkats, ostriches, pigs, ray-finned fish, snails, squids, trees and whales, to name a few.

Splice
"A genemod in which an animal, plant or other naturally occurring, but non-human, genotype is modified with elements of both human and other non-human genomes, usually for service, companionship, or hedonistic purposes."

- Encyclopedia Galactica on splices.

A splice is a lifeform resulting from the artificial combination of genetic material from different species. Arguably, the most famous clade in Orion's Arm is the "Siberoo", a synthetic hybrid of Siberian tiger and red kangaroo. Just like regular animals, splices can also be provolved, as in the forementioned splice clade. There are 3 quadrillion splices.

Rianth
A rianth, short for therianthrope, is any human who has been genetically modified to express traits of other naturally-occurring species. Rianths are human splices, i.e. a genetic recombination of a human and another species.

Tweak
"Generic term for human or other biont in which the original genotype has been optimized for existence in extreme environmental conditions. Though many nearbaseline humans have modifications that allow them to survive in conditions outside the range suitable to baseline humans, tweaks are so radically changed that they are not interfertile with human baselines or nearbaselines. In the extreme cases they may have human-like form and psychology but lack any genetic or even biochemical overlap with the original human type."

- Encyclopedia Galactica on tweaks.

A tweak is a lifeform that has been biologically altered to live in new, radically different environments. Tweaks are extremophiles, and there are about 9 quadrillion in the Terragen Sphere. Examples include humans that have been adapted to live exposed to the vacuum of space or the cold of Titan-like moons.