Paradoxically, the People's Republic of Terra has achieved the dream of every Communist political theorist of the 19th century and beyond, while at the same time evolving into something utterly unimaginable to them.
On its surface, the Republic is the Communist utopia. Everyone is entitled to equal food, funds, shelter, and employment—all provided by the government. When you look closer, things become almost comically muddled.
With their conquest of Earth achieved, the early Republic found itself needing to evolve rapidly to accommodate the cultures of Earth and prevent an endless series of rebellions. Thus began the process of cultural assimilation.
In the end, three cultures became the societal pillars of the Republic:
Many cultures around the world had some form of these pillars already in place, allowing for easier acceptance. The remaining population of North America, for example, could latch onto the idea of self-made people rising to the top in society and held an almost religious reverence for the military. Many Asian cultures not already consumed by the People's Republic of China practiced some form of ancestral worship or remembrance.
In practice, these cultural traits mingled with local expressions of similar ideas and evolved into the social system the Republic has today.
At the top of society are the Zhizheng Guan (Consuls) and the Noble Houses that evolved from the old oligarchs. There is frequent overlap between the two groups, but technically, the role of Zhizheng Guan is open to any Republic citizen who can earn it, while the Noble Houses require either birth, marriage, adoption, or a high enough level of wealth or fame to buy out or earn a noble title.
Below them sits wealthy non-Nobles and high-ranking military officers (usually famous Captains or higher), top executives, media figures, and anyone with ludicrous amounts of wealth who have yet to reach for nobility. You will often find the heads of organized crime houses rubbing shoulders with wealthy merchants, film stars, corporate executives, and Flag Officers at functions at this level.
Below them sits the rest of the officer ranks, high-ranking non-commissioned officers, junior executives, stars that have yet to break out on a galactic level, and those comfortably in the "millionaire" bracket.
Below that is what would have once been the middle class: enlisted soldiers, white-collar managers, lawyers, doctors, and academics.
Below that are the blue-collar workers, skilled or specialized labor, farmers, and local shop owners.
At the very bottom are those who rely almost exclusively on governmental aid. They are frequently drafted as soldiers or guided into day-labor work in government farms, factories, mines, and other facilities. However, keeping with the communist ideals that were resurrected and perfected, even those at the bottom rung of society are housed, fed, provided the standard citizen income, and given full medical care.
It is entirely possible to improve your lot in society. In fact, many within the Terran system would say that doing so is the goal, or even the duty, of the average citizen.
Typically, the lower rungs are progressed through via self-improvement: pursue a better job, higher education, or learn a new skill that can propel you to a higher rung.
The higher rungs are also fairly mobile. As long as you have and maintain the right level of wealth or fame, you're in. Even the Nobility is not a closed ecosystem.
At the formalization of the Nobility, 200 noble houses were created, though only 10 were filled on that day. In the intervening centuries, that number rose to around 120 noble houses, though a good 40 of those are in danger of losing that status should anyone come along with an offer to buy out the title. The remaining 80 unclaimed titles had their price of entry set exponentially higher than it typically costs to buy out an existing title.
If someone intends to purchase a title currently held by a Noble House, they must gain the approval of ten other existing houses. The house they are purchasing must have a currently living and legitimate heir. Any house without an heir (like the near-mythical House Simon) is held in stewardship by the Office of the Peerage, under the Premiere.
Houses held in stewardship are held for no less than one century to allow time for a scion of the House to make themselves known. That scion may elect to take up the House's Title (either to sell it or claim it for themselves) or reject it. If rejected, the title is placed in limbo for twenty years for the scion or their heirs to reconsider, then moved to unclaimed status.
Every five years, Peerage Day is held in either Moscow, London, or New Delhi. This day is a holiday across the Republic that often features lavish public parties thrown by the Nobility.
At a ceremony in that year's city, every Noble House is either reaffirmed, passed into Stewardship, or granted to the new holder of the Title.
Useful note if you're in a major city on Peerage Day: the best parties are thrown by new Title holders or by one of the original 10. House Qadir's are near legendary.
The capital system of the Terran government is Sol, the home solar system of the human race. A majority of the system is now populated with colonies and outposts, but the Terrans have been reluctant to do much mining, wanting to keep the solar system as pristine as possible. Even the asteroids first mined during the Republic's initial expansion were catalogued, and replacements of similar size and composition were brought in from the Oort Cloud and set in similar orbits.
The Sol System is also the military hub of the Republic. Earth Station serves as the main command and control facility for both Navy and Army. Two massive shipyards exist in-system for construction, repair, and refit of military vessels—one in Mars orbit, the second in orbit around Neptune. Two massive detection stations were constructed at the L4 and L5 Lagrange points, with a secret fallback facility, Point Reckoner, at the L3 point, housed in a captured asteroid and officially referred to as a backup supply depot and marshalling yard.
Earth remains the capital world of the People's Republic of Terra, despite some early factions wanting to build a paradise world elsewhere. They saw Earth as dirty and scarred, but not yet lost. That is also a primary reason why such proposals meet opposition—there's a sense of pride and legitimacy that comes from their government's seat being the homeworld of Humanity.
The seat of government resides in a city constructed in the Mongolian steppes specifically for that role: Renlei Heping ("Human Peace").
This is the accepted language of the Terrans. It is the only language spoken in schools until the age of six, then students are required to become bilingual with English.
Outside of Terran territories, Mandarin is rarely used, as all Terrans are required to learn English and it's the primary language of the League already.
English is considered a "universal" language, as the League (and to a lesser extent the Terrans) have popularized its use across most of Human controlled space. Since the NorAellians and Lyndri have to trade with Humans, most have had to learn to speak it.
Russian is still spoken in the former Russian territories on Earth and is very common in Freelance space. The Russian territories are allowed an exemption to learning Mandarin from birth; they are taught Russian first, then Mandarin and English at age six.