iOS Learning notes---network requests

I. The concept of the HTTP protocol

HTTP protocol: Hyper text Transfer Protocol (Hypertext Transfer Protocol) is a transport protocol used to transfer hypertext to a local browser from a World Wide Web server. HTTP is an application-layer protocol, consisting of requests and responses, and is a standard client server model (c/s)

Features of the HTTP protocol

Support client/server mode (c/S mode)

Simple and fast

Flexible, HTTP allows any type of object to be transferred, the type of the object being transmitted is tagged by content-type