In a technical sense, a consumer VPN service is really more of an encrypted proxy than anything else. It tries to obfuscate what network traffic and activity you’re actually participating in by both appearing as the endpoint for your connection, and the destination for the connection of the sites you visit and internet services you use.
A true VPN does more than that, allowing multiple computers that are not sharing a router to communicate with each other as if they are. For context, certain IP addresses are local-only, such as any IP starting with 192.168.x.x. This means that when you access the broader internet, your IP is different than the one used when you try to use your WiFi printer on your same network. They’re both your addresses, you have them at the same time, but one is really the address of your whole network while the other is the address of your computer in that network. Think “building street address” and “office number in that building”
For businesses and other organizations, a VPN is a useful way to allow users to connect using these local-only addresses without physically being connected to the network those local addresses are valid in. You don’t have to expose the printer to the Internet, you just need to expose the VPN service to the Internet, and then allow VPN users to connect to the network when they need to use the printer