A "Reaction GIF" is a short, looping video clip that captures a person's emotional response, often used in online conversations. These GIFs are typically taken from movies, TV shows, or viral videos and are shared on social media platforms to express feelings like joy, anger, or surprise. Users often insert Reaction GIFs into messages or comments to enhance their communication, making it more engaging and relatable. The popularity of Reaction GIFs has grown with the rise of platforms like Twitter, Reddit, and Tumblr, where users can easily find and share these expressive clips.