Stewart By your description, a VPN probably isn't a VPN either, its "more of a proxy that allows you to pass your connection through" whatever.
A VPN is a secure connection to some network that is mostly closed off to the outside world, such as an office LAN. You use VPN software to gain Virtual access to the Private Network. In other words, to access non-public resources in a closed off / private network without exposing those resources to the internet.
When you're using a VPN as a privacy screen, you aren't using it to gain access to resources on a private network. You're using it to access publicly accessible resources, but hiding your identity behind someone else's IP address. That's using it like a PROXY, not like a VPN. Its called VPN only really because it uses VPN software and protocols.
Now Orbot, on the other hand, can be used in exactly the same way, with greater privacy effect because of the different layers and different entry and exit nodes (whereas a typical privacy "VPN" will have a connection IN, and a connection OUT that could potentially be associated by data volume), but Orbot can ALSO be used as a more traditional VPN in that it also does provide access to a PRIVATE NETWORK -- known sometimes as the dark web.