Computer Network Reading Notes (2)

COOKIE: indicates the status information transmitted between the HTTP server and the customer, the identifier, (similar to the ID card number)

Purpose: It is generally used for the server to track client activity on the server.

When you browse a website, the web server places a very small text file on your hard disk, it can record your user ID, password, browsed webpage, stay time, and other information.

Two points about cookies:

1. Cookie is only a small text file, not an executable file of a computer. Therefore, it is impossible to spread computer viruses or obtain information from users' computer hard disks. And can only be read by the website provider.

2. Because cookies can also be used to collect users' behaviors on the web site. This leads to a double-edged sword: it brings us both convenience and privacy leaks.

Cookies

Almost all website designers use cookies when designing websites, because they want to provide users with a more friendly and human-culture browsing environment, at the same time, it can collect visitor information more accurately.

HTML: the standard language for making web pages, which eliminates the barriers to information exchange between different computers. (The tags of HTML documents are displayed by the browser ).

The dynamic and static documents are mainly reflected in the server section, mainly because the document content is generated differently.

Browser screen display continuous update technology

Server push)

All work is handed over to the server, which is constantly running on applications associated with dynamic documents.ProgramRegularly update information and send updated documents.

Disadvantage: the server overhead is too large; the number of TCP connections between the server and the browser is large, and the network transmission latency is increased.

Activity documentation Technology

All work is transferred to the browser. When a browser requests an activity document, the server returns a copy of the activity document program to run the program on the browser. Java is a technology used to create and run activity documents.

Browser

Consists of a group of client programs, a group of interpreters (HTML interpreters are required), and a control program. The control program manages these client programs and interpreter programs, which are the core component of the browser.

API

The system call interface is actually an interface for converting the control right of the application process and the control right of the operating system. Because the application needs to write some programs before using the System Call, especially many parameters in the system call, this system call interface is also called an API.

Socket

A socket interface is an application programming interface that the supplied program uses TCP/IP. As long as the application uses the TCP/IP protocol for communication, it must interact with the operating system through the socket (this requires the system to call the function) and request its service.

◆ Socket is a mechanism used by an application process to interact with the operating system for the purpose of obtaining network communication services.

March 10