Okay kiddo, so there is a man named the Aga Khan. He is a very important leader who is like a king or president for some people called the Ismailis. They live in different parts of the world and follow a religion called Ismailism.
The Aga Khan's real name is Prince Shah Karim Al Hussaini. He was born in Switzerland a long time ago in 1936. He became the Aga Khan when he was only 20 years old, after his grandfather passed away.
Now, the Aga Khan does lots of things to help the Ismailis and other people around the world. He helps people who are poor, sick or don't have access to education. He also tries to improve the environment and works to make the world a better place.
The Aga Khan also has lots of cool things that he takes care of like beautiful gardens, buildings, and museums. These places are called the Aga Khan Development Network, which is like a big group that helps people in different ways.
So overall, the Aga Khan is a very important person who helps people and tries to make the world a better place for all of us.