Where I live, a graduate with an MBBS degree (Master of Medicine, Master of Surgery) is called a doctor. To me, strictly speaking, he is a doctor only...
In computer networking, a virtual storage area network (VSAN) is a collection of ports from a set of connected Fibre Channel switches, that form a virtual fabric. Ports within a single switch can be partitioned into multiple VSANs, despite sharing hardware resources.
A VPN (virtual private network) is software that connects your computer to another computer (a VPN server) somewhere else in the world. The connection between your computer and the VPN server is encrypted. That is what a VPN is, but a pay-for VPN service offered by a third party is slightly different.