Subsidization is when someone gives you a little bit of extra money to help pay for something. It's like getting an allowance from your parents. Let's say you want to buy a toy that costs $10 but you only have $5. Your parents might give you the other $5 so you can buy the toy. That's a kind of subsidization.
But sometimes, it's not your parents who give you the extra money, it's the government. They do this to help people who really need it or to help important things, like farmers. For example, the government might give some extra money to a farmer to help them grow more food for everyone. This helps both the farmer and the people who need food. So subsidization can be really helpful for everyone.