Dffits is a big, complicated word, but it's actually kind of easy to understand! Here's a simple explanation for you.
Imagine you have a group of friends, and you want to pick someone to be the leader of your group. You might have a list of things you want your leader to be good at, like being organized, friendly, and good at making decisions.
But what if one of your friends seems like they would be a great leader, but they're actually not? Maybe they're really good at making decisions, but they're not very organized, and that makes things harder for everyone else in the group.
That's where dffits comes in. It's a way to figure out if someone in your group (or something else you're studying) looks like they're really good at something, but actually they're not.
Dffits calculates a kind of measure of how much influence one observation has on the overall analysis. It tells you if one observation is having too much influence over the whole analysis, and causing the results to be skewed.
Think of it like a scale that shows how much weight each person in your group is carrying. If one person is carrying too much weight, they might be making it hard for everyone else to walk. Dffits is like a way to measure how much weight each person is carrying, so you can make sure everyone is balancing things out and making things easier for the whole group.
So basically, dffits is a tool that helps you make sure your analysis is accurate and fair, by making sure that one observation isn't skewing the results too much. It's kind of like making sure everyone in your group is doing their fair share of the work, so that no one person is carrying too much weight.