Prime

Primes, Also kwon As outsiders are planeswalkers or people within the planes that were originally born on a prime material plane, Such as Toril, oreth, or athas. while citizens of sigil can vary in looks and culture there is a sense that it all blends in and creatures one singular culture, for primes it is the opposite, while the outer planes are finite the amount of prime material planes is virtually unkown.
for example, a human from the city of waterdeep is going to be a very different person than a dwarf from the wasteland of athas. one was raised in a city full of magic and various races walking around interacting and drinking at taverns. while the other grew up in a harsh dessert with no magic and no gods, struggling to find water for the day.
it would be a bit pointless to list specific details of primers because its impossible to tell if what one prime tells you will be the same from the next.