Which automation tool relies on YAML for its configuration files?

Ansible is the automation tool that relies on YAML (YAML Ain't Markup Language) for its configuration files, known as playbooks. YAML is a human-readable data serialization format that is commonly used to define configuration settings in a straightforward way, making it easier for users to understand and manage automation tasks.

In Ansible, playbooks utilize YAML syntax to describe the desired state of systems without requiring a complicated structure. This simplicity allows users to write configurations that are easy to read, write, and maintain.

While Puppet, Chef, and SaltStack have their own methods and formats for defining configurations, such as Puppet's DSL or Chef's Ruby-based recipes, they do not use YAML as their primary configuration language. This distinction highlights Ansible's focus on ease of use and accessibility, which is a key aspect of its appeal among network and system administrators.