To be honest, there is an issue with marketing yoyos. The Duncan butterfly is considered to be a beginner yoyo. Not because it is a better fit for beginners, but because of the price point.
I have found that the more expensive a yoyo is, the more it is considered a professional yoyo from the promotional materials
From my experience a beginner yoyo is easy for a new player to pick up (so like a responsive yoyo that allows the player to get used to using the yoyo).
If someone were to ask me what the difference between a beginner and an intermediate player. I would say the person needs to have the skills equivalent to being able to bind, and can hit the trapeze trick semi consistently to be an intermediate player.