Imagine living in a big castle, with knights walking around, people wearing fancy clothes, and kings and queens ruling over everything. This is what it was like during the medieval times.
Now, imagine if people today wanted to go back to this time period, and live like they used to. They might wear similar clothes, have similar jobs, and live in big castle-like homes. This is called neo-medievalism.
Basically, it's like pretending to be in the medieval times again. Just like playing dress-up and pretending to be a princess or a knight, except some people take it very seriously and like to live their lives this way.
However, it's important to remember that life in the medieval times was very different than it is today. People didn't have technology like we do, and life was much harder. So while it might be fun to pretend sometimes, it's important to also appreciate the way we live today.