A VPN protocol makes a VPN tick, affecting important factors like speed and security. Here we compare the most widely used protocols. Speed and security are about the same for OpenVPN and L2TP/IPSec. OpenVPN is an excellent open-source protocol, but many users struggle to set it up properly. It is a secure protocol but not super-fast (not super-slow either) In speed and privacy it is on par with OpenVPN, it is easier to set up unless you have to bypass a firewall.”]
Source: https://blog.malwarebytes.com/explained/2021/05/vpn-protocols-explained-and-compared/