Process browser to access the website:
1, the user inputs a URL.
2, the browser requests the DNS server to acquire the corresponding IP address.
3, requesting a connection to the IP address of the server
4, transmits a resource request (HTTP protocol).
. 5, Web server receives the request, parses the request and determines user's intention.
6, the user wants access to resources.
7, the http server returns the resource to the program.
. 8, the http server program sends data over the network resource to the browser.
9, browsing parses presents data requests.
10, what domain is it?
On a computer when we access a server, you need to remember the IP address of the server, because the IP address is not conducive to people's memory, so the launch of the domain name technology domain name is separated by a series of dots composed of Internet names or the group name of the computer, the computer identifies the location in data transfer.
The domain can be used to represent a unit, agency or individual can use to determine the name or location on the Internet domain name is unique. Customers can use this name to find information about products and services.
DNS What is it?
Since we use the domain name to identify a computer's location, but we have said before, that uniquely identifies identifies the host on the network is an IP address, so we need to record it, a corresponding relationship between domain names and IP addresses, the corresponding relationship is stored in DNS server when we make a request to DNS, DNS will return to our domain name corresponding to the IP address.
TCP 三次握手 ：
1. 客户端 发出 SYN包--------》 服务端
2. 服务端 发ACK包给客户端，同时发SYN包
3. 客户端 发ACK包