These comments are all so aggressive, let me try answering this in a less rude way.
App is short for application, at the end of the day no matter where you install an app from an app is a packaged chunk of software meant to accomplish a task. Microsoft word is an app, chrome is an app, flappy bird is an app, calculator is an app, any "program" that you launch is an app.
Now where the waters get muddy is app stores. App stores such as the apple store or Google play are apps specifically built to help you install other apps. The intent of these is to provide users a safe location they can search for other apps and install them without fear of viruses and receive updates automatically. Windows and Linux have their own app stores too, the windows store, though sad and decrepit is supposed to provide the same assurances as Mac's app store.
Now can you use the computer without apps? Yes! Your computer just won't do much since you've forgone your calculator, games, and any other purpose built software you might have installed.
Can you use the computer without the "app store"? Yes! You can install the application from anywhere, it doesn't need to be the app store. Apple and Google get a cut of the money made by apps sold on the app store. Because of this they are incentives to discourage users from installing apps from elsewhere. They've called installing apps from elsewhere "side loading" in order to make it sound scary and not normal but it is in fact the normal way we have been installing apps since before these app stores arrived.
The last type of app I want to call out because it's a bit different. Web apps are apps you can use by going to a web page. These apps are installed on someone else's computer and you get to use it when you open the page. It's still an app, you just don't have to install it. There are special types of computers (for example. Chromebooks) that are built around these types of apps.
Hope this helps!
Yes. Absolutely. Privacy is for everyone.
You are assuming that the things legal and illegal today will continue to align with your morality. "I don't do anything bad" only holds value while you and your governing body share beliefs.
What if tomorrow you disagree? Suddenly there would be a long history of potentially incriminating internet history associated with you. What if it's for something you can't even control, such as "using the internet while female" in a society that recently banned women from using the internet?
This level of paranoia shouldn't be required yet look at the state of the world.
A VPN doesn't just allow you to change your location. It's a tunnel between you and someone you trust (a VPN provider). All your traffic shows up as originating from the trusted partners address do that it cannot be traced back to you. They offer this to lots of customers and if your VPN provider is worth their salt, anonymizes these interactions so that they can't even tell people who did what.