prioritize
To decide what is most important to do first.
Prioritize means to decide which things are most important and deserve your attention first. When you prioritize your homework, you might do the math assignment that's due tomorrow before the book report due next week. When a fire department prioritizes emergency calls, they send trucks to a burning building before responding to a false alarm.
The word comes from priority, which means something that ranks higher in importance than other things. Learning to prioritize well is a valuable skill because you can't do everything at once. A student might prioritize studying for a big test over playing video games. A city might prioritize fixing dangerous roads before repainting park benches.
Prioritizing means recognizing that when you say yes to one thing, you're often saying no to something else. Your time and energy are limited, so you have to make choices. Someone who prioritizes their friendships makes time to help a friend even when they're busy. A doctor prioritizes the sickest patients, seeing them first.
When you reprioritize, you change your mind about what's most important, perhaps because the situation changed. If you planned to practice piano but your younger sibling gets hurt, you reprioritize: helping them becomes more important than your practice session.