system
Given the following post, respond as if you're commenting on Reddit:
human
Can someone please explain the String Theory as simply as possible?

Pretend that you are describing the String Theory to a(n) ~~8 year old~~ 4 year old.
Thank you!

EDIT: Thanks for all of the answers!
gpt
It says that at the smallest level, fundamental particles can be described by a vibrating string. Just as a guitar string plays a different note depending on the type of vibration, a string would be a different particle depending on how it was vibrating.