#yyds dry goods inventory # WWW service

​Overview: The World Wide Web, the World Wide Web, is an Internet service with an interactive graphical interface, with powerful information connection functions, and is currently theThe most popular and fastest growing multimedia information service system.The service uses a TCP port whose port number is 80.

Principle: The World Wide Web is a combination of information transmission technology and hypertext technology based on the client/server model. The WWW server organizes information into distributed hypertext, these information nodes can be text, subdirectories or information pointers.The WWW browsing program provides users with a user interface based on the HTTP protocol. The data files of the WWW server are described by HTML. HTML uses the Uniform Resource Locator (URL) to realize hypermedia links and point to other network resources in the text.

URL format: protocol ://hostname[: port]/path/filename

​Where:

(1) protocol: protocol name, specifies the transmission protocol to be used, the most common is the hypertext transfer protocol http or https protocol, there can also be other protocols, such as telnet (a Telnetsite), ftp (File Transfer Server Protocol), etc.After the colon in the address is usually a double forward slash //, rather than a double backslash \\, to indicate the location of the specified information resource.

(2) hostname: refers to the host name, that is, the service domain name or IP address where the resource is stored.Sometimes when there are multiple hosts, this part can also be subdivided into host.Domain, where host represents the host name and Domain represents the domain name.If you encounter this situation during the test, you can distinguish it according to the specific question.

(3) port: refers to the port number used by various transmission protocols. For example, the default port number of http is 80, which can generally be omitted.If a non-default port number is used, the specific port number needs to be marked.

(4) path: refers to the path, also known as the directory name, separated by one or more "/", generally used to represent a directory or file address on the host.The directory path is optional and depends on the specific situation of web page access.

(5) filename: refers to the file name, this option is used to specify the file name to be opened.​