<human>:  What is the difference between a VPN and a proxy server?
<bot>: The main difference between a VPN and a proxy server is that a VPN provides a more secure connection, encrypting all of the data that passes through it, while a proxy server only works at the application layer, providing an intermediary server that masks the true IP address of a user. Additionally, a VPN will also hide all of the user's traffic from a web server, whereas a proxy server will only allow certain types of traffic to pass through.