What are cookies used for?

Cookies have five functions: "session management", "personalized experience", "cross-page data transfer", "advertising targeting" and "analysis and statistics": 1. The client in subsequent requests Identify yourself by sending this cookie, and manage the user's session state accordingly; 2. Store the user's preferences, interface layout selection, language selection and other information; 3. Used to transfer data between different pages; 4. Track users’ interests and activities; 5. Record user behavior and access information.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

Cookies have the following common uses in web development:

1. Session management: The most common use is for session management between the client and the server. When a user visits a website, the server can create a cookie containing a unique identifier and send it to the client. The client identifies itself by sending this cookie in subsequent requests, and the server can manage the user's session state accordingly, such as staying logged in, tracking the user's shopping cart, etc.

2. Personalized experience: Cookies can be used to store user preferences, interface layout selections, language selections and other information to provide users with a personalized experience the next time they visit.

3. Cross-page data transfer: Cookies can be used to transfer data between different pages. When a cookie is set on one page, other pages can read and use the data in the cookie.

4. Advertising Targeting: Cookies are also used by advertisers to track users’ interests and activities to push relevant advertisements to users.

5. Analysis and statistics: By recording user behavior and access information in cookies, the website can perform analysis and statistics to understand users' access habits, traffic sources, etc.

It should be noted that the use of cookies must comply with relevant privacy policies and laws and regulations to protect users' personal information and privacy. At the same time, developers should pay attention to properly setting the expiration time, scope, security and other attributes of cookies to ensure their normal and safe use.

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