A VPN routes a device's internet traffic through an encrypted tunnel to a server elsewhere, which both secures the connection (useful on untrusted networks like public Wi-Fi) and makes the traffic appear to originate from wherever that server is located rather than the user's actual location.
For SEO specifically, that location-masking is the more relevant feature: search results, especially for local and commercial queries, vary meaningfully by geography, so checking how a page or a competitor actually ranks in a different country or city often requires appearing to search from there. A VPN offers a rough, low-cost way to do that, though it's an imprecise tool for the job: VPN exit nodes are often shared across many users and don't always map cleanly onto specific cities the way dedicated rank-tracking tools with true local data centers do. For a quick, informal check on how a SERP looks from another country, a VPN is good enough; for accurate, repeatable local rank tracking at scale, a dedicated tool built specifically for that purpose is the more reliable choice.
