A habit is like a routine that your brain automatically goes to without you even having to think about it. It's like when you wake up in the morning and brush your teeth before school, or when you come home from school and immediately head to your room to play video games.
Your brain likes habits because they help make things easier and more efficient. It doesn't have to work as hard to figure out what to do next because it already knows what your routine is.
Sometimes habits can be good, like remembering to do your homework every night before bed. But other times they can be bad, like biting your nails or eating unhealthy snacks all the time.
If you want to change a habit, it can be hard at first because your brain is used to doing things a certain way. But with practice and determination, you can create new habits that are healthier and better for you.