In Ursula LeGuin's Earthsea books, magic is accomplished when wizards learn the true names of things. Discover the true name of fire, and it is yours to command. In fairy tales, if you learn Rumplestilskin's name, the evil sprite is banished. Speak of the Devil, though, and he shall appear.
Names have power, especially in fiction.
Use the right names, and the characters and places you write about assume added depth and resonance. Use the wrong ones, and your story at best will be forgettable, at worst, laughable. Mainstream writers can use the names of friends, relatives and co-workers. They can set their stories in their hometown and use the names of its diner, high school, laundromat, altered only slightly, if at all. All suitable for a science fiction or fantasy story.