VPN stands for Virtual Private Network, and it's a browser extension that blocks websites from accessing websites from unknown domains, both malicious and benign. By doing so, it helps protect user privacy and blocks trackers and ad servers from accessing your browsing activity. However, just using a VPN isn't enough for secure browsing. You need to be cautious and use it responsibly, especially when visiting unknown websites. Always ensure that the websites you visit are legitimate and from trusted domains.