The majority of humans in the 50th century live in indentured servitude to the nobility. Illiteracy is the norm and few serfs ever venture more than a day's walk from their home. The average technology level is pre-industrial and most never see anything more sophisticated than the firearms issued to local law enforcement or an occasional motor vehicle. The marvels of spaceships and jumpgates and aliens are little more than fairy tales to nearly three quarters of the population. Serfs derive what little they know of the universe from the Church which keeps them fearful and insular. Demons and sorcerers are believed to be lurking in the dark corners of the world, just waiting to tempt or devour those who stray from the Light. Advanced technologies are seen as the tools of the heretics and the diabolists. Sadly, much of what the Church teaches is actually true.
About 20% of the population of the Known Worlds are freemen, craftsmen, free labourers, militiamen and merchants. They fill all the roles in society not covered by the Church, the League or the Nobility, although most are employed by those institutions. Most freemen are at least somewhat literate and have travelled more widely than the average peasant. A few have travelled in space and some even work on spaceships. These freelancers are referred to as yeomen and many adventurers come from this class.
The final 5% of the population are the nobles, the guilders and the priests. The are educated and have knowledge and skills which would be forbidden to people of lower classes. Indeed, some have knowledge which is forbidden to anyone, but enjoy the protection of the organizations to which they belong. Most have travelled in space and for those who haven't, it is a choice, not a necessity.