One another is a phrase that describes people or things doing something back and forth between themselves. When classmates help one another with homework, each student helps others and receives help in return. When soccer teammates pass to one another, the ball moves between different players on the team.

You often use this phrase when talking about groups of three or more people or things interacting together. Friends might encourage one another before a big test, meaning everyone in the group gives encouragement to everyone else. Animals in a pack protect one another from danger. Musicians in an orchestra listen to one another to stay in sync. Some people also use one another when talking about just two people, similar to each other.

The phrase emphasizes mutual action and connection. When people respect one another, it's not one-sided: the respect flows in all directions. When neighbors look out for one another, each person watches over the others. This reciprocal quality, meaning everyone giving and receiving, is what makes one another different from phrases like “each person” or “everyone.” It highlights the back-and-forth nature of relationships and interactions in a group.