Both VPNs and proxies enable a higher degree of privacy than you might otherwise have, allowing you to access the internet anonymously by hiding your IP in various ways. But how they do that is quite different.
Proxy acts as a gateway and only works for some websites一it's ideal for basic functions like anonymous web browsing and managing (or circumventing) content restrictions. Proxy servers excel at IP masking and misdirection, making them good for viewing geographically limited content. They allow users to bypass content restrictions and monitoring, or enforce website content restrictions
A VPN client on your computer establishes a secure tunnel with the VPN server, replacing your local ISP routing. VPN connections encrypt and secure all of your network traffic, not just the HTTP or SOCKS calls from your browser like a proxy server.