Opera VPN is definitely a VPN service as it uses VPN protocols to connect to you to a different network. However the data passed through is not encrypted in transit and it is only encrypted at rest. OpenVPN is a dedicated VPN product that allows you to import VPN profiles and connect through it.
Well actually Opera uses an SSL proxy so it does encrypt traffic in transit that is the main purpose of a VPN. It does NOT encrypt anything at rest an no VPN does. That is where tools like VersaCrypt and Bitlocker come in. These encrypt data at rest or in other words not in use.