Hey there kiddo! So, have you heard about warriors and fighters of ancient Japan? They were called Samurai and they used to protect the country from enemies. The Shogun is kind of like their boss or leader.
You know how in school, there's a principal who takes care of everything and everyone in the school? In a way, the Shogun is like the principal of all the samurai warriors. They make important decisions, lead the army, and work towards keeping everyone safe.
The word Shogun actually means "supreme commander" and they were like the big boss of everyone in Japan. They were very respected and powerful people as they held the highest position in the government.
I hope that helps you understand what a Shogun is!