Okay kiddo, so imagine you and your friends are trying to decide what game to play. Some of your friends want to play soccer and some of them want to play tag. You're not sure which game you want to play, but you know that you're the only one who hasn't picked a side yet.
This is kind of like how some states in America are called "swing states" during an election. You see, during an election, there are two main groups called political parties. They are the Democrats and the Republicans. Each party has their own ideas about how things should be run in the country, and they try to convince people to vote for them.
Now, most states usually vote the same way in every election. For example, if you go to Texas, most people there usually vote for the Republican party. If you go to California, most people there usually vote for the Democratic party. These states are called "safe states" because they are pretty predictable.
But there are a few states that are not as predictable. These states are called swing states. They are like you in the example before, because they are not sure which party to vote for. Sometimes they vote for the Democrats, and sometimes they vote for the Republicans. These states are really important during an election because they can help decide who wins.
Just like how you might decide to play soccer or tag depending on what your friends are saying, swing states might vote one way or the other depending on what the candidates are saying. So during an election, the candidates spend a lot of time and money in these states trying to convince people to vote for them. And that's why swing states are so important!