What is a YAML file? A complete guide from basics to practical use

YAML is a human-readable data serialization language, often used for configuration files. It's primarily used in Kubernetes, Ansible, and other tools that handle data configuration. YAML's structure relies on indentation, making it more readable than formats like JSON, which uses braces. Files can use the extensions `.yaml` or `.yml` interchangeably. YAML data structures consist of collections and scalars, with collections encompassing sequences and mappings. Compared to CUE, YAML lacks schema validation but offers simplicity. YAML is fundamental in defining structures within CI/CD pipelines, such as those within GitLab. It's employed in various applications, including configuration management, due to its readability. Understanding YAML simplifies the configuration of systems, making them easier to manage. YAML's popularity stems from its readability, versatility, and support for multiple data types.