About the mechanism of the Web and HTTP

Browser and server

The browser is the screen that is currently displayed The server is like a big PC that stores various data Displayed in the browser by downloading the file from the server The file contains information such as HTML, CSS, JS, etc.

It looks like this in the figure 　　　　　　 (Browser) ←←←←←← (Server) File 　　　　　　　(HTML,CSS,JS) HTTP What is HTTP? How to interact with the browser and server Basically request and response

request 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← response

The request throws the desired information to the server and the server returns that information. It is the server-side language that creates the rules for exchanging this request and response.

4 basic HTTP methods

  1. Get GET data Used when displaying a web page

I want to see this page 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← Page information

  1. Send POST data Used to save data in forms etc.

Save the data 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← I saved it

  1. Update PUT data Used when rewriting existing data

Change the data 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← I changed

  1. DELETE data deletion Used when erasing existing data

Erase the data 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← I erased it

If you compare it with Twitter View Tweets GET New Tweet Post POST Tweet update PUT (Twitter should not have been possible) Tweet deletion DELETE

IP address and domain

An IP address is like an address assigned to data in a server and is managed numerically. What is a domain? The "~~ .com" part Since it is difficult to understand if it is an IP address, a system called DNS links the IP address and domain.

Until the last website (Qiita) is displayed

Please tell me the IP address of qiita.com 　　　　　　→→→→→→ (Browser) (DNS) 　　　　　　←←←←←← Returns the IP address

GET request to IP address obtained from DNS 　　　　　　→→→→→→ (Browser) (Server) 　　　　　　←←←←←← Returns HTML, CSS, JS

It's like this

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