Clojure is a modern programming language that runs on the Java Virtual Machine (JVM). It is designed for functional programming, emphasizing immutability and first-class functions. This means that data structures in Clojure cannot be changed after they are created, which helps prevent bugs and makes code easier to reason about. Clojure is known for its simplicity and expressiveness, allowing developers to write concise and clear code. It also supports concurrent programming, making it easier to build applications that can handle multiple tasks at once. With a strong focus on software development, Clojure is popular for building web applications and data processing systems.