attention
The mental focus you give to something you notice.
Attention is the mental focus you direct toward something. When you give your attention to your homework, you're concentrating on it rather than thinking about video games or what's for dinner. When a teacher asks for your attention, she wants you to stop whatever else you're doing and focus on what she's about to say.
Attention works like a spotlight in your mind. You can only shine it on one thing at a time, though it can shift quickly between different things. Some activities demand intense attention: reading a complex chapter, building something intricate, or listening to important instructions. Other activities require less: you might hum a familiar song while walking down the hallway without thinking much about either one.
People talk about paying attention because focus costs something. It takes mental energy. When you pay close attention to something, you're investing that energy carefully. When your attention wanders, your focus has drifted away without you meaning it to. Some things grab your attention suddenly, like a loud noise or someone calling your name. Other things require you to direct your attention deliberately, choosing to focus despite distractions.
The ability to control your attention helps you face harder challenges in school and in life.