说明：  本书前半部分由HTTP的成长发展史娓娓道来，基于HTTP 1.1 标准讲解通信过程，包括HTTP方法、协议格式、报文结构、首部字段、状态码等的具体含义，还分别讲解HTTP通信过程中代理、网关、隧道等的作用。接着介绍SPDY、WebSocket、WebDAV等HTTP的扩展功能。作者还从细节方面举例，让读者更好地理解何为无状态（stateless）、301和302重定向的区别在哪、缓存机制，等等。本书后半部分的重心放在Web安全上，涵盖HTTPS、SSL、证书认证、加密机制、Web攻击手段等内容。
(The first half of this book is based on the growth and development of HTTP. It explains the communication process based on HTTP 1.1 standard, including the specific meaning of HTTP method, protocol format, message structure, header field and status code. It also explains the role of proxy, gateway and tunnel in the process of HTTP communication. Then it introduces the extended functions of HTTP such as spdy, websocket and WebDAV. The author also gives some examples from details to help readers better understand what is stateless, what is the difference between 301 and 302 redirection, caching mechanism, and so on. The second half of this book focuses on Web security, covering HTTPS, SSL, certificate authentication, encryption mechanism, Web attack means and so on.)