This can be anything from Hyperspace in Star Wars, Warp Drive in Star Trek, travel through the Warp in Warhammer 40k or anything else.
I’ve always liked “slow” FTL travel, where going a few light-years still takes a few days or so. I also really like travel through an alternate dimension like in 40k, Event Horizon, Witchspace in Elite Dangerous.
I wanna know your favorite versions, or do you prefer stories that obey the laws of known physics, like the Expanse or Rimworld?
FTL travel in the series of book “the interdependency” is one of the major plot devices, so it’s one of those that marked me the most.
Without going into spoilers: FTL is limited to using a natural phenomenon that are pretty much akin to space-rivers, so humanity has no power onto what systems are connected to one another.
As rivers do, those “currents” can also shift and have done so in the past: the place where the books happen are completely cut off from earth since pretty much forever, for example.