YAML (YAML Ain't Markup Language) is a human-readable data serialization standard that is often used for configuration files and in applications where data is being stored or transmitted. It is designed to be easily readable and writable by humans, while also being easily parsed by computers. YAML is often used as an alternative to XML or JSON, especially when readability is a priority. It supports a variety of data types, including scalars (strings, numbers, booleans), sequences (lists), and mappings (dictionaries or associative arrays). YAML files typically use indentation to define the structure of the data, making them visually clean and easy to understand. The format is widely used in DevOps for configuration management, in programming for data exchange, and in various other applications where structured data needs to be stored or transmitted in a human-friendly format. Its flexibility and readability have made it a popular choice for many developers and system administrators.