Haskell is a functional programming language known for its strong static typing and lazy evaluation. It allows developers to write code that is concise and expressive, making it easier to reason about programs. Haskell is often used in academia and industry for tasks that require high reliability and maintainability. One of Haskell's key features is its use of pure functions, which means that functions do not have side effects and always produce the same output for the same input. This characteristic helps in creating predictable and testable code. Haskell also supports advanced concepts like monads, which facilitate handling side effects in a controlled manner.