What apps require root that you want? I would highly advise against rooting if you can help it, because especially if you don't know what you're doing, there is very high potential to brick your device or open up security issues. I would recommend learning what root actually means and what it entails, and learning everything that happens when you root so you can decide for yourself if that's something that is necessary. Rooting modern hardware just to run an app is not really all that important nowadays. You might as well buy an android that has a custom OS already installed centered around privacy if that's your thing.
Additionally, to actually answer your question, adb is not root. It is just a development bridge that lets your PC talk to your phone, so you can push apps or do other development related stuff. It just happens to be a part of the toolset when rooting.