Marginal seat

Okay, imagine you're playing musical chairs with your friends and there's one chair left. That last chair is a really important chair because if you don't get it, you'll be out of the game.

Now, in the world of politics, there are places where people vote to choose who they want to be in charge. These places are called constituencies. A marginal seat is a constituency where the vote is really close, meaning the two biggest parties have almost the same number of people who support them.

Think of it like musical chairs. The two biggest parties are fighting over that last chair, and whoever gets it wins the game (or in politics, the election). That's why politicians focus a lot of attention on marginal seats - they're really important to win so they can have power over the country.