YAML, which stands for YAML Ain't Markup Language, is a human-readable data serialization format often used for configuration files and data exchange between languages with different data structures. Its simplicity and readability make it a popular choice among developers for defining complex data structures in a clear and concise manner. Unlike JSON, which can be more rigid and less intuitive, YAML allows for comments and supports a variety of data types, including scalars, lists, and dictionaries. This flexibility makes it particularly useful in applications like Docker and Kubernetes, where configuration management is crucial.