Firstly, don't worry about what you'd call it. You don't need to label the piece you're doing in any way - just write something *good*.
Otherwise, I think you're getting confused between narration and focalisation. Narration is about the 'person' telling the story. Third person is where author-god/fly-on-the-wall/voice-outside-the-story is telling the story. Focalisation is about the perspective of the story. If it's told from one character's perspective, it's called internal focalisation; if it's told from purely outside perspective, not knowing what anyone is thinking or feeling, it's called external focalisation.
You can mix up both narrative voice and focalisation, but you just need to be aware of what you're doing and do it logically for your reader. For example, author-god third person narration can see inside people's heads and hearts, so it's okay to focalise through different characters at different times.