Shen is a word from the Chinese religion and spirituality that means something like "spirit" or "divine energy" or "godly power" - kind of like the 'powers' superheroes have in the comic books. Just like we humans have different types of emotions and qualities that make us unique, the shen are believed to have their own unique personalities.
Shen is often associated with the natural world in Chinese religion - with things like the sun, moon, mountains, forests, and rivers. Some shen are believed to be helpful and friendly to humans, while others can be quite scary and dangerous. But generally, the shen aren't seen as single beings to be worshipped, but rather as a part of a much larger cosmic system that we human beings are just a tiny part of.
So, in short, shen is a word that describes the powerful and mystical energy that exists in the natural world in Chinese religion - something that we humans can't fully understand or control, but that can have a big impact on our lives.