Kaftherians are not so different than Earthlings in many ways. They are evolved humanoids, living on a planet that developed very much like Earth did. They revolve around one sun in their solar system, their planet's surface is largely comprised of water, and many species of plant and animal developed similarly to ones you and I might know. They have a political system and a justice system, largely ruled independently from country to country, and currency.
There are however, a few notable differences. Firstly, the lifespan of a Kaftherian citizen is approximately two hundred fifty years, as their bodies have evolved further throughout the millennia, causing the adult aging process to slow. Children still grow rapidly, reaching maturity in their teen to twenties, however the average woman or man can remain youthful and healthy for over two hundred years, making them appear between twenty and forty years of age in earth terms.
Secondly, while they maintain what we on earth see as standard human looks, hair, skin and eye color in neutral tones, they also developed more brilliant and remarkable colors for their bodies naturally. Kaftherians can be found in infinite color combinations depending on region and class. It would seem, the healthier, wealthier blood lines developed these traits more quickly, whereas the low class, muddy bloodlines remained more neutral and 'unremarkable', as they called it.
Thirdly, while their genetics improved beyond that of current Earth's, their technology had not. They are slower in the race for technological improvement, remaining relatively satisfied with basic communication lines and entertainment, something like the nineteen eighties or nineties of earth's history. The exception to this thinking was in the ways of medical technology. There, while having genetically eradicated many forms of disease naturally, there was very little they couldn't cure. They'd also developed a completely universal language.
Perhaps the most notable difference, however, is that the vast majority of the planet, instead of working to eradicate and abolish slavery, it was embraced and standardized. It was as commonplace in to own a slave in their world as it would be to own a vehicle in ours, and they were manufactured, purchased and traded in much the same way. Slaves were not classified by skin color or region of birth, but simply by genetics and characteristics.
The slave bloodlines date back tens of thousands of years, and knowledge of what inspired the first slaves to be chosen has been lost over time. It's long been myth that the first slaves submitted themselves, but it's unknown if the belief holds any truth. While not built in factories like vehicles, they were bred in clinical facilities both by the government and private breeders, and sometimes by private citizens in their own homes.