What exactly are proxy and VPN often mentioned?

Recently, some websites cannot be accessed due to the proxy being turned on. After turning on the VPN, the proxy will open inexplicably. These problems are very confusing, so I devoted myself to researching what these terms mean, what they do, how to use them, etc.

“Technology is a double-edged sword, it depends on the user.”

1. What is an agent?

        ~~~~~~~         A proxy (Proxy is a server or service that acts as an intermediary between a client and a target server. When you send a network request, the proxy server makes a request to the target server on your behalf. data and forwards the response to your device. The proxy server acts as a relay station, processing your request and delivering the data to you while hiding your real IP address.

Note: When choosing to use a proxy server, make sure you choose a trustworthy service provider

Some proxy servers may log your online activity, while others may be used maliciously to steal personal information

2. What is VPN technology?

        ~~~~~~~       **VPN (Virtual Private Network)** is a technology that protects user privacy and security by creating an encrypted tunnel on a public network. It creates a virtual private networkon the Internet by establishing a secure connection between your device and the VPN server, encrypting and transmitting your network traffic to the target server. a>.

        ~~~~~~~       When using a VPN, all your network traffic is encrypted to prevent third parties from intercepting or spying on your data. VPN technology can effectively protect your privacy and security.

3. Functional differences between proxy and VPN

        ~~~~~~~       The main function of a proxy server isto act as an intermediary between the client and the target server. It can hide your real IP address, help you bypass geo-restrictions, implement access control and filtering, and provide caching and acceleration features. Proxy servers are usually used on a local scale, such as in a company's internal network, to manage and control internal network access.

        ~~~~~~~       And a VPN is a technology that protects privacy and security bycreating an encrypted tunnel over a public network. Its main functions are to encrypt your data traffic, hide your real IP address, bypass geo-restrictions and provide a secure network connection. VPN is widely used in personal and business fields to protect personal privacy, provide secure remote access and connect networks distributed in different regions.

        ~~~~~~~       While proxy servers and VPNs have similar functionality in some ways,a VPN offers more comprehensive privacy and security protection because it encrypts the entire network connection and not just Is the traffic of a browser or a specific application. Additionally, a VPN can establish secure connections across different networks, allowing you to access remote resources and protect sensitive data.

The common functions can be briefly summarized as the following five points:

1. Hide real IP address
2. Access control and filtering
3. Caching and acceleration
4 . Bypass geographical restrictions
5. Encrypted communication

4. Specific settings of the agent (taking win11 as an example)

        ~~~~~~~       First find the proxy interface in win11 system settings, as shown below:

In the proxy settings, you can choose the following two options:

1. **Automatically detect proxy settings:** This option allows your device to automatically detect the presence of a proxy server on your network and configure the proxy settings based on the detection results. The system will attempt to automatically detect the address and port of the proxy server and use that proxy server for network connections.

2. **Manually set proxy:** After selecting this option, you can manually enter the address and port of the proxy server, and then click the "Save" button to apply the settings. You can get proxy server details from your network administrator or proxy service provider.

5. Other doubts

5.1 How do some websites detect that you are using a proxy?

        ~~~~~~~       There are many ways for websites to detect proxy servers, including checking the IP address of public proxy servers, analyzing the network behavior patterns of proxy servers, using anti-fraud technology, etc.

5.2 Why do some websites detect the use of proxy servers and deny access?

1. Prevention of Abuse and Security Issues: Some websites prohibit access to proxy servers to prevent abuse and maintain security. Proxy servers can be used by malicious users to hide their true IP addresses and identities in order to conduct inappropriate activities, such as voting, launching attacks, or committing illegal activities. To reduce this abuse and protect the security of the site, these sites may disable proxy server access.

2. Maintain geo-restrictions and access controls: Some content providers restrict access to their content based on geographic location. Proxy servers can be used to bypass geo-restrictions and allow users to access restricted content. To maintain copyright and content distribution compliance, some websites detect the use of proxy servers and block access that bypasses geo-restrictions.

5.3 Why does the proxy automatically turn on when turning on the VPN?

        ~~~~~~~       In some cases, when you turn on the VPN, the system may automatically turn on the proxy. This may be because your VPN client or operating system has relevant settings configured. Here are some possible reasons for this behavior:

1. VPN provider configuration: Some VPN providers integrate proxy functionality into their client software and tie it to the VPN connection. The purpose of this is to increase privacy and security by using both a VPN and a proxy server to hide your real IP address and further protect your data.

2. Operating system settings: Some operating systems (such as Windows) provide a unified network settings interface, allowing you to configure a proxy server when configuring a VPN connection. When you enable a VPN connection, the operating system automatically associates the proxy settings with the VPN connection and enables the proxy during the VPN connection.

3. Router-level VPN connection: If you are using a router-level VPN connection, the router may be configured with a proxy server to handle all network traffic passing through the VPN. This ensures that all devices connected through the VPN can benefit from the proxy server's capabilities.