The one and only thing a VPN does is that it switches your IP to another. It has absolutely nothing to do with privacy or security. An IP-address is just a single metric among hundreds that are used on the web to track users. IPs are also typically not equal to a user. It is common that an IP is a set of users and IPs often change when it comes to consumer ISPs. VPN makes sense in TCP-scenarios like Bittorrent but for web it is pretty much useless in itself.