RAML (RESTful API Modeling Language) is a tool used to define RESTful Web Service API specs.
You can read the tutorial Introducing about RAML for an overview of it. In this tutorial, I summarize the tutorials of Huong Dan Java about RAML for your reference.
Basic
In this tutorial, I will guide you all on how to define request URL with RAML.
In this tutorial, I will guide you all on how to define request body and response with RAML.
In this tutorial, I introduce with you all about data types in RAML.
In this tutorial, I introduce with you all about Trait in RAML.
In this tutorial, I introduce with you all about API fragments with RAML.
Usage
In this tutorial, I will guide you all on how to import API specs defined in RAML file into Postman.
In this tutorial, I guide you all on how to generate API contract using Spring MVC-RAML Plugin.