If you've been shopping for a VPN service, you've undoubtedly come across a bunch of names like SSL, OpenVPN, SSTP, L2TP/IPSec, PPP, PPTP, IKEv2/IPSec, SOCKS5, and more. These are all communication protocols. They are, essentially, the name of the method by which your communication is encrypted and packaged for tunneling to the VPN provider.There is a lot of debate among security purists about which VPN protocol is better. Some protocols (like PPP and its tunneling variant, PPTP) are old and compromised. Others, like SSTP, are proprietary to one company or another.My recommendation -- and the protocol I most often choose to use -- is OpenVPN. OpenVPN is a non-proprietary, open-source implementation of a VPN communication layer protocol. It's well-understood, well-regarded, generally quite secure, and robust. Also, it has the benefit of communicating over port 443, which is the standard port for https communication, which means almost all firewalls will allow OpenVPN traffic -- and most won't even be able to detect that a VPN is being used.Yes, there are certainly other protocol choices, even some that might be more appropriate than OpenVPN in certain situations. But if that's the case, either you've already made that decision, or your IT organization has specified a specific protocol you should use. However, as a default, if you're not sure what to look for, look for OpenVPN.