What was the movie Cam about?

I recently watched the movie "Cam" on Netflix and somehow I couldn't see what it was about, how could the person steal their identity at all, who looked exactly like them, would love me look forward to an answer.

It wasn't a person, it was either old videos of her that were being played back or a projection.

It was a computer simulation (AI) that took over / stole the identity of the women (who also died).

You notice that at the end when they both face each other and the AI does not recognize the original.