Gapps (Google Apps) are just a bunch of closed-source and non-free applications. They are not a part of the operating system and they are not required for the o

Gapps (Google Apps) are just a bunch of closed-source and non-free applications. They are not a part of the operating system and they are not required for the operating system to work. Just like you can use Ubuntu without Ubuntu One, you can use Android without Google Apps. Unless you absolutely need a Google app like Gmail, it won't be an issue. Even then, you can use the browser (which is open source) to go to gmail.com etc. As for the manufacturer ROMs, they are not Android. They are Android-based operating systems and they have their own names such as TouchWiz, Sense etc. This article is specifically talking about the Android operating system, which means it is referring to AOSP rather than, say, Touchwiz.