Disparate impact is a big and complicated concept, but I'll try to explain it in a way that a 5-year-old can understand.
Let's say there are two groups of people who want to play a game of tag. Group A has 10 people, and all of them are quick runners. Group B also has 10 people, but only 5 of them are quick runners, while the other 5 are slow runners.
Now, if both groups play the game of tag, the chances of Group A winning are much higher because all of their players are quick runners. Group B, on the other hand, has half of their players who are slower, making it more difficult for them to win.
This is a bit like what happens with disparate impact. It means that when a rule or decision is made, it can affect one group of people more than another, even if the rule is meant to be fair. This can happen because of things like differences in education, income, or other factors that might make it harder for some people to access certain opportunities.
When a rule or decision has a disparate impact, it can be a problem because it means that some people are being treated unfairly, even if it wasn't intentional. So, it's important for people in charge to think about these kinds of things and make sure that everyone has an equal opportunity to play the game.