Proxies and VPNs both reroute your traffic through another server, which is why people mix them up, but they solve different problems.
What a proxy does
A proxy typically reroutes traffic for a single app or protocol at a time — your browser, or a specific script — and usually doesn't encrypt the connection between you and the proxy server itself unless you're specifically using an HTTPS proxy.
What a VPN does
A VPN encrypts all traffic leaving your device at the operating system level, covering every app at once, not just a browser. It's built with privacy and security as the primary goal, not just IP masking.
Where they overlap
Both can make it look like your traffic originates from a different location, which is why either can be used to access region-restricted content. For that narrow use case, they achieve a similar result through different means.
Which to choose
For scraping, automation, or per-app IP switching, a proxy is the more natural and often cheaper tool. For general privacy and security across your whole device, a VPN is the better fit.