It means AI that is General, as in it is not specific to one narrow task, like object recognition or playing chess.
This was a hard problem for decades. No AI was general, until GPT 3 or 4. Now we have General AI.
So we have AGI.
GPT6 will attempt to do almost any problem you can give it in text or image format and it will actually do a decent job a lot of the time. But its performance is still extremely spiky and it still makes basic mistakes and hallucinations.
So it's definitely a general artificial intelligence in some sense but it's kind of a weird one compared to the classic scifi idea