What is the difference between a VPN and a proxy?
Short answer
A VPN creates an encrypted tunnel at the network/OS level, so all of a device's traffic is routed through it and protected end to end — used for secure remote access. A proxy operates at the application level, relaying traffic for specific apps or protocols and not necessarily encrypting it. The big differences are scope (whole-device vs per-application) and that a VPN encrypts by design while many proxies do not.
People reach for "VPN" and "proxy" interchangeably, but they operate at different layers and offer different guarantees. The interviewer wants to see you separate scope from encryption.
What a VPN does
A VPN builds an encrypted tunnel between your device and a VPN endpoint, operating at the network/OS level. Once connected, essentially all of the device's traffic — every app, every protocol — is wrapped and routed through that tunnel. This gives confidentiality and integrity for data in transit (protecting you on untrusted Wi-Fi) and lets a remote user appear to be inside a private network for secure remote access. Protocols include IPsec and WireGuard.
What a proxy does
A proxy is an application-level relay. It forwards traffic for a specific application or protocol (an HTTP proxy for a browser, for example), and the client must be configured to use it. Crucially, a proxy does not inherently encrypt the traffic it relays — it changes the apparent source and can filter or cache, but the payload may still be plaintext unless the application itself uses TLS.
The key differences
- Scope: VPN = whole device; proxy = per-application.
- Encryption: VPN encrypts by design; proxies often don't.
- Layer: VPN at network layer; proxy at application layer.
- Purpose: VPN for secure access and privacy; proxy for filtering, caching, access control, or simple IP masking.
A common pitfall is assuming a "free proxy" gives the same privacy as a VPN — it may log everything and add no encryption.
Interviewers want the scope-and-encryption contrast and a clear statement that a proxy is not a substitute for a VPN's confidentiality.
Likely follow-ups
- Does a proxy provide confidentiality the way a VPN does?
- What is split tunneling and what are its risks?
- When would you choose a proxy over a VPN for a specific use case?