2.1 Document Organization / 文档结构

The HTTP/2 specification is split into four parts:

• Starting HTTP/2 (Section 3) covers how an HTTP/2 connection is initiated.
• The frame (Section 4)and stream (Section 5)layers describe the way HTTP/2 frames are structured and formed into multiplexed streams.
• Frame (Section 6)and error (Section 7) definitions include details of the frame and error types used in HTTP/2.
• HTTP mappings (Section 8)and additional requirements (Section 9)describe how HTTP semantics are expressed using frames and streams.

HTTP/2规范分为四个部分：

• 开始HTTP/2一节( 第3章 )涵盖了怎样初始化一个HTTP/2连接。
• 帧层( 第4章 )和流层( 第5章 )两章描述了HTTP/2帧怎样被构造并形成多路复用的流。
• 帧定义( 第6章 )和错误定义( 第7章 )包含了HTTP/2的帧和错误类型的细节。
• HTTP映射( 第8章 )与附加要求( 第9章 )描述了HTTP语义是怎样用帧和流来表达的。

While some of the frame and stream layer concepts are isolated from HTTP, this specification does not define a completely generic frame layer. The frame and stream layers are tailored to the needs of the HTTP protocol and server push.

尽管一些帧和流层的概念与HTTP是相脱离的，但本规范没有定义一个完全通用的帧层。这些帧和流层是根据HTTP协议和服务端推送的需求量身定制的。