What does the RAML specification define in an API context?

The RAML (RESTful API Modeling Language) specification is primarily focused on defining the methods and data types that an API uses. This includes articulating the structure of the API, outlining its endpoints, request methods (such as GET, POST, PUT, DELETE), and the data formats that can be expected in requests and responses (such as JSON or XML). By using RAML, developers can create clear and concise documentation that not only communicates the functionality of the API but also aids in the design and implementation of the API itself.

The emphasis on methods and data types in RAML ensures that developers understand how to interact with the API effectively, including what input is required and what output can be expected. Consequently, this enables better collaboration among teams and facilitates the development process by providing a blueprint that both human and machine can understand.

The other options, while related to API design and usage, do not capture the primary role of RAML. For instance, the rules for validating API requests are part of implementation but not the core focus of RAML. Network security protocols would fall under the domain of API security practices rather than the definition of the API itself, and deployment stages pertain to the operational lifecycle of the API application rather than its specification.