Found here an explanation why the 'present perfect' is called like that and why it's 'perfect'. For the record: "As to why it's perfect, the term comes from Latin perfectus, "achieved, finished, completed". Which is quite literally what you have done whenever you have done something." But, I'm still confused, because of this example:
She has lived in this city for ten years.
The action is not finished. She is still living. Why then link the word 'perfect' to Latin perfectus that means finished, completed?