YAML is a human-readable data serialization standard used in configuration files and data exchange. It is designed to be easy to read and write, making it a popular choice for defining configuration settings, data structures, and application states. YAML uses indentation to represent the structure of data, supporting complex nested data without the need for additional syntax. It is widely used in DevOps tools and frameworks such as Ansible, Kubernetes, and Docker Compose for configuration management and orchestration. YAML's simplicity and readability make it an efficient way to manage configuration data in a clear and organized manner.