You know how when you start a new game or start a new day and you say to yourself, "Today, I'm going to be better"? That's kind of what a New Year's resolution is! It's a promise you make to yourself that you're going to try to improve something about yourself or your life in the coming year.
For example, you might say, "I want to eat healthier foods" or "I want to clean my room more often". These are things that you think will make you feel better or happier. Sometimes people make really big resolutions, like "I want to read a book every week" or "I want to run a marathon!"
The thing about New Year's resolutions is that they can be really hard to keep. You might start off really strong, but then you forget or get busy and don't stick to your plan. That's okay, though! The point of a resolution is to try your best and make progress, even if it's not perfect.
So, if you have something you want to work on in the new year, make a resolution! Write it down somewhere and keep it in mind. And most importantly, don't get discouraged if it's tough. You can do it!