Okay kiddo, flow in policy debate is like taking really good notes. You know how you take notes in school when your teacher is talking? It's just like that, but in debate we use a special way of taking notes called a "flow".
When two people are debating, they are saying a lot of different things. They might be arguing about what the problem is, what causes it, and how to fix it. But to keep track of all of these different arguments, we use a flow chart. It's kind of like a map that helps us keep track of everything that's being said.
The flow chart has different sections, like one section for the first person's arguments and another section for the second person's arguments. And when someone says something new, we write it down in a new box on the flow chart.
This way we can see all of the different arguments and how they connect to each other, just like a map shows all of the different roads and paths you can take to get to different places. And then at the end of the debate, we can look back at our flow chart and decide who had the best arguments and who won the debate.
So flow is just like taking really good notes, but in a special way that helps us keep track of everything that's being said in a debate.