[Notes] How is the network connected-1. Browse to generate messages

Concept record

• URL: Uniform Resource Locator, uniform locator;
• FTP : File Transfer Protocol ；
• HTTP: Hypertext Transfer Protocol, Hypertext Transfer Protocol;
• URI: Uniform Resource Identifier, resource identification symbol;
  generally speaking, the content of URI is a file name for storing web page data or a file name of a CGI program. Various access targets can be written, which are collectively called URI ;

HTTP

URL

The browser is like a multi-functional client. We can not only access the web server, but we can use the first word to distinguish the things it does, which is "http", "file" and so on;

Chapter 1 Browsing to generate messages-exploring the inside of the browser

Parse URL

The end point must be the file name, if you can't find it, it's only possible that someone is lazy to omit it.

Quiz

1. What does http in http://www.nikkeibp.co.jp/ mean?

Answer: http protocol

2. What is the difference between the following two URLs?

a. http://www.nikkeibp.co.jp/sample
b. http://www.nikkeibp.co.jp/sample/Answer
: a visits the file "sample", and b visits the directory "sample" Default file;

3. What is the address used to identify computers and servers connected to the Internet?

Answer: IP address

4. What is the name of the server used to query the IP address based on the domain name of the web server?

Answer: DNS server

5. What is the name of the program that sends the request message to the DNS server?

Answer: parser

standard answer

1. HTTP protocol (see [1.1.1])
2. The sample in a represents the file name, and the sample in b represents the directory name (see [1.1.3])
3. IP address (see [1.2.1])
4. DNS server (see [1.2.3 and 1.3])
5. Parser (see [1.2.3])

noun

Resolver

1. From the perspective of the application that calls the resolver, I only need to give the resolver a domain name, and the resolver can analyze it and find me an IP address;
2. Convert the domain name into an IP address;