So, there are some people who live in a place called Cuba, and some people who live in a place called America. Some of the people who live in America are originally from Cuba, and they care a lot about what happens in Cuba.
These people have organized themselves into a group that tries to convince the American government to do things that will help Cuba become a better place. They call themselves the Cuban-American lobby.
They do this by talking to important people in the American government, like the president or senators, and telling them why it's important to help the people in Cuba. They also work together to give money to politicians or political parties who agree with their ideas.
Just like when you ask your parents for things you want, the Cuban-American lobby is constantly asking the American government to do things that will help their cause. Sometimes they get what they want, and sometimes they don't.