various network protocols

Recognize URL

What we commonly call "URL" is actually what we call URL

HTTP protocol format

HTTP request

HTTP Response

HTTP methods

get method

• Get the corresponding resource information directly
• The get method can take parameters (the url's ? is followed by get parameters)
• Handling of insensitive data

post method

• The data is submitted to the server through the body, not through the url
• post-"cont-length: text
• Processing encrypted content data

The difference between get and post: post can pass more parameters than get and is more private.

HTTP status code

Common HTTP Header

• Content-Type: data type (text/html, etc.)
• Content-Length: Length of Body
• Host: The client tells the server that the requested resource is on which host and which port
• User-Agent: declares the user's operating system and browser version information
• referer: The page from which the current page is redirected
• location: used with 3xx status code to tell the client where to visit next
• Cookie: Used to store a small amount of information on the client side. Usually used to implement the function of session