Far future in fiction

In some stories, people imagine what the world will be like many years from now. Sometimes, they imagine that things will be really cool and exciting - maybe we'll have robots and flying cars and live on other planets! Other times, they imagine that things will be really scary and dangerous - maybe there will be wars or monsters or the planet will be destroyed. When people write stories about the far future, they're trying to imagine what it might be like and tell us all about it so we can understand what's possible and what we should be working towards.