Ruby is a programming language that is dynamically typed, object-oriented, and interpreted. It was created in the mid-1990s by Yukihiro "Matz" Matsumoto in Japan, and it has since become popular worldwide for its simplicity, expressiveness, and flexibility. Ruby is often used for web development, as it has a number of libraries and frameworks that make it easy to build and deploy web applications. It is also used for a wide range of other tasks, including data analysis, automation, and systems programming.