Okay kiddo, so a long, long time ago, people used to make things with their hands, like toys, clothes, and tools. This was called the "industrial" era. But now, we have machines that can make things for us instead of us making them ourselves!
So, when we talk about a "post-industrial" economy, we mean that we've moved on from making things with our hands and we focus more on providing services and information. That means people are working in jobs like doctors, lawyers, teachers, and software engineers, instead of working in factories.
This new type of economy is based on knowledge and technology, and it's all about using creativity and innovation to come up with new ideas instead of just making things. It's kind of like using your brain to solve problems instead of just using your hands.
So, in a post-industrial economy, we don't need to make as many physical things because we have machines and processes that can do it for us. Instead, we focus on using our brains to create new things and help people in different ways. Pretty cool, huh?