Artificial Intelligence Explained for My Grandpa

My grandpa recently discovered that I've been writing medium articles. After reading a few that I wrote about AI, he sent me a text asking for me to write an article explaining it to "seniors" like him. This is my best attempt at that. Artificial Intelligence (AI) is a phrase used by computer scientists to describe programs that can do things that require applying knowledge. But isn't any computer program'applying' the knowledge given to it in its own programming?