Fantasy Counterpart Culture
Fantasy Counterpart Culture is a /tg/-relevant term shamelessly stolen from our frenemies over at TVTropes. In a nutshell, worldbuilding is hard, so, what's one way to make it easier? Why, it's to take real life cultures and slap them into your game!
There's... not much more of a way to describe it. The phenomena of Fantasy Counterpart Cultures is wide-spread, and has been going on at least as long as /tg/ has existed - Dungeons & Dragons (and, by inheritance, Pathfinder) is infamous for it. It's an easy way to get a solid base, and whilst it can be executed in a lazy fashion - the Knorrmen of Jakandor are such a blatant mish-mash of Viking and Native American it makes one roll the eyes - it's not inherently bad.
Fantasy Counterpart Culture is particularly likely to be used in a lazy fashion when dealing with "exotic" (to the author) cultures. It's a recurring issue for Oriental Adventures, and Maztica has been blasted for how lazily it does "South American Fantasy" by literally just putting South America in the Forgotten Realms.