Backend development?

So what we've been learning about in class and what I've learned on my own time only covers one half of being a developer. There's another side of this called the backend and it looks way more complicated than the frontend. I seen a joke on the internet where there was a illustration of the frontend as a friendly, colorful, and magically place to make a website. They only have to focus on what the user sees and experience while using the site. The backend on the other hand was painted as a dark, swampy, and mess place where there's a lot of things that need to get the site working. There was another field called a full stack developer where someone can do both the frontend and backend. I didn't think there was so much that goes into getting a website or application to work. Might have to learn a little bit of backend to add to my list of skill.