Ios_ Network _01 Basic knowledge

First, the network programming concept 1, what is the network

(1) In the field of computer, the network is the virtual platform of information transmission, receiving and sharing, through which the information of each point, polygon and body is connected together to realize the sharing of these resources .

(2) How to identify each computer on the Internet-- IP address

An IP address is used to number a computer on the internet and is not easy to remember .

People are more accustomed to using domain names to access computers on the network

(3) How to access resources on the Internet-- Agreement

Computers in a network must speak the same language if they are able to communicate smoothly with each other, and the language is equivalent to a protocol. such as the HTTP protocol

(4) How to locate resources on the Internet-- URL

The Uniform Resource Locator (Uniform Resource Locator, abbreviated as URL) is a concise representation of resource location and access methods on the Internet, and is the address of standard resources on the Internet. Each resource on the Internet has a unique URL that contains information that indicates the location of the resource

How data is transferred on the Internet- binary stream

2. url example (URL)

3. Network access

4. Steps to establish a network connection

(1) Determine the URL: Identify the network resources you want to access

(2) Establishing a network request (urlrequest)

(3) Send the request (URLRequest) to the server

(4) processing the data returned by the server

Ios_ Network _01 Basic knowledge