Presentation layer state transitions
Representational State Transfer
In REST's name "presentation layer state transition", the subject is omitted. The "presentation layer" actually refers to the "presentation layer" of "Resources".
URI becomes the address or unique identifier of each resource
The specific form of the "resource" is called its "representation layer" (Representation).
For example, text can be expressed in txt format, HTML format, XML format, JSON format, or even binary format; pictures can be expressed in JPG format or PNG format.
The Internet communication protocol HTTP protocol is a stateless protocol. This means, all state is kept on the server side. Therefore, if the client wants to operate the server, it must use some means to make the "State Transfer" happen on the server side. And this transformation is based on the presentation layer, so it is "presentation layer state transformation".
What is RESTful Architecture:
(1) Each URI represents a resource;
(2) Between the client and the server, a certain presentation layer of this resource is transferred;
(3) The client operates the server-side resources through four HTTP verbs to achieve "presentation layer state transformation".
Four verbs expressing the mode of operation: GET, POST, PUT, DELETE
SOAP（Simple Object Access Protocol）：
Simple Object Access Protocol is a lightweight, simple, XML -based ( a subset of the standard Universal Markup Language ) protocol