A response is an answer or reaction to something that was said, done, or happened. When your teacher asks a question and you raise your hand to give an answer, that answer is your response. When you knock on a door and someone opens it, their action is a response to your knock.

Responses can take many forms. They might be words, like when you write a response to a friend's letter. They might be actions, like when a goalkeeper makes a quick response to block a shot. They might even be feelings, like when your heart pounds in response to a scary scene in a movie.

The word suggests a connection between two things: something happens first, then comes the response. A fire alarm rings, and firefighters respond by rushing to help. A student asks for help, and the teacher responds with an explanation. Scientists study how plants respond to sunlight by growing toward it.

In everyday conversation, people often use respond and reply interchangeably, but respond feels slightly broader. You reply to a specific question or message, but you respond to all kinds of situations: emergencies, challenges, opportunities, or even changes in your environment.