The document discusses RESTful web services and different types of web service architectures. It defines web services as a method of communication between electronic devices over a network. RESTful web services use HTTP methods like GET, POST, PUT, DELETE to convey method information and URIs to specify scoping information. Other architectures may use XML bodies or SOAP headers instead of HTTP methods. Web services can be classified as RESTful, RPC-style, or a REST-RPC hybrid based on how they handle method and scoping information.