First, the software architecture
1, C / S: client / server
2, B / S: browser / server (currently used)
Second, the network resources
1, static resources
Static Resource : The results of all users access after, obtained are the same, called static resources, static resources can be resolved directly browser.
如：html，css，JavaScript...
2, dynamic resource
Dynamic resource : the results for each user access to the same resources, the same may not be obtained. After the dynamic resource being accessed, you need to convert a static resource, and then returned to the browser.
如：servlet/jsp，php，asp...
Resource Access diagram:
Third, the three elements of the communication network
1、IP
IP address : an electronic device (e.g., a computer) that uniquely identifies the network.
2, port
Port Number : The application uniquely identifies your computer. (0 to 65536)
3. Transfer Protocol
Transfer Protocol : provides rules for data transmission
The basis of the agreement :
① TCP: security protocol, three-way handshake, at a slower pace.
② UDP: insecure protocol, fast.