Okay kiddo, imagine you have a bunch of toys scattered all over your room. If you want to find a specific toy, you have to search through all of them to find it. That's like having a stovepipe system - everything is separate and not connected, so finding what you need takes a lot of work.
Now imagine you have a toy chest where all your toys are neatly organized and easy to find. That's like having an integrated system, where everything is connected and easy to access.
In the grown-up world, a stovepipe system refers to different parts of a company or government agency that don't communicate or work together very well. For example, say the Department of Transportation wanted to build a new road. But the people in charge of buying the land don't talk to the people in charge of designing the road, who don't talk to the people in charge of hiring construction workers. If each of these groups works independently, the road might not get built well or on time.
So, just like organizing your toys, it's better for everyone to work together in an integrated system. This makes things easier, faster, and more efficient, so that everyone can reach their goals more easily.