Some hobbies have a rich history or background.
While it's not necessary to know the background in order to enjoy the hobby, it can sometimes enhance the experience. For example, a hobby site about mask making might include some information on this page about the history of masks. My Background I might also use this page to describe my own personal history regarding my hobby. For example, if I'm describing boatbuilding, I might mention how I first became interested in boats and how I acquired my skill.