Don’t they both hide your actual IP address?
VPN is a virtual private network. It’s like your local network, where all your devices can talk to each other. But it’s built over the internet. And all members of the private network aren’t actually ‘connected’ directly. So it’s a VIRTUAL network.
You can run a VPN over your local network at work, and your remote workers will interact with your in office workers as if they are in the office. They can share files, access the corporate software, etc.
Proxy server is a server that sends your data in your stead, and from the point of the receiver it feels like data is coming from the proxy server and not from you.
They both allow you accessing web resources without giving away your real IP. But they are made differently.
And there are other ways to hide your IP, like a tor network.