From W3C Wiki
The specification architecture of the Web defines a few principles and guidelines which help understand the way the Web is suppose to interoperate.
Understanding Web Architecture
The document is mainly written for Software engineers as an audience. A Web site is the work of many persons. Specifically in a commercial context, a Web site is the results of the work of BusinessStrategist, VisualDesigner, ContentEditor, SeoExpert, AnalyticsExpert, UxDesigner, WebDeveloper (FrontEnd and BackEnd), ProjectManager, AccountDirector. All these people are working in the WebAgency for a client. All of these people have a diverse understanding of the Web and WebArchitecture. Some of these understandings have a big impact on the way the Web site will be working.