Worldbuilding (Conworlding)
Worldbuilding is about building your own world! A glimpse into a fictional setting. You can use your world ideas for stories, or games, or just create it for the fun of it. Worldbuilding is a must-have skill for anyone who is interested in dreaming up a fictional world.
The alternative term "conworlding" is also used. In addition, variations of it are frequent. You can focus on a single aspect of your world, and signal that it's fictional by putting "con" in front of the topic. Conhistory for example, would be focusing on the historic political events of your world.
You can enjoy creating any part of a fictional world you like. Some people have been known to start with maps (conmapping), others start with whole languages. Anything you want to invent can be your main or only focus. This hobby is an important aspect part of several others, but it can also be a thing you enjoy for its own sake as well.