When creating a work of fiction it’s important as the creator of that fiction to world build. There’s a lot that goes into whatever place you decide to set your story. Whether the story takes place in a fantasy world within the real world like Harry Potter, or a completely made up world Like Lord of the Rings, it’s important to have the knowledge of that world that you’ve placed your characters in. In works of fantasy or science fiction especially, I personally believe as a writer, you have to have intimate knowledge of the world you’ve created for your characters the same as you would for the characters you’ve made. A lot of those details about whatever world you’ve made won’t even make it in your story. The reader won’t know the significance of that tree you put into that scene, or the history that took place on that road before your character began walking on it, and that’s fine. As long as you know as the writer that’s all that matters. I think creating a world with a vast history, giving it some life before, during and after the protagonist arrives makes it more fun and even helps in the process of the writing by generating new ideas as your story progresses.
Now that’s not to say you should have a set-in-stone idea of this world’s history before you start writing word one. When I started writing my latest story, I had a vague idea of the world I had placed my character in and everything that happened before. But as I went on, and more and more ideas came to mind, the more the history of the world that I had made became more clear. I knew what happened in certain parts of this world that made it why it is, though I never touch on it in the story, because that information isn’t vital to the overall storyline itself. The ideas and history that have spawned from me writing about this world has given me enough background story that, if I want to, I can actually write about this world in later books…but that’s way down the road, if I even chose to.
Creating whole other worlds is a good way to practice writing. Even if you don’t have a story, or characters to inhabit it, sometimes just having a vision in your head of a world and writing down what it looks like, what it does and how it feels can spark the imagination where a story and characters can come to fruition. And that is one of the best things about world building.