others
People who are not you or your group.
Others are people besides yourself or besides a specific person or group you're talking about. When your teacher says “help others,” she means people around you who need assistance. When you wonder what others think about your science project, you're curious about the opinions of your classmates, not just your own.
The word creates a simple but important division: there's you (or your group), and then there's everybody else. If five students volunteer for the school play and you're one of them, the other four are the ones who aren't you. If your family visits relatives, your parents might say “the others will arrive later,” meaning the relatives who haven't shown up yet.
Others appears in common phrases that express important ideas. “Some people like chocolate, others prefer vanilla” shows that people have different preferences. When someone talks about caring what others think, they mean worrying about other people's judgments.
The word simply acknowledges a basic truth: you're one person in a world full of people, and others refers to everyone else.