Sword and planet is a type of science fiction story that usually takes place on a different planet, far away from Earth. The main character is often a strong, brave hero who carries a sword and fights against evil aliens or creatures to save the day.
Think of it like when you play with toys and have a hero figure who goes on adventures to save other toys from monsters or villains. Except in this case, instead of toys, it's a story and instead of a hero figure, it's a character in a book.
These stories often include things like spaceships, advanced technology, and different species of creatures living on these faraway planets. But usually, the hero relies on their sword and bravery to defeat their enemies.
So, in short, sword and planet stories are science fiction adventures that take place on different planets with heroes who use swords to fight against evil creatures.