This is obviously a huge issue, that we do not have time to cover.
For an introduction to how science (rather than, say, science fiction)
addresses these questions, see:
The Mind's I, Hofstadter and
Dennett, 1981. - Library, 155.2.
- A mind-bending collection of essays exploring the possibilities
of Strong AI. If Strong AI was true, could you be immortal?
Could you copy brains?
Sometimes I link to Wikipedia.
I have written something
In defence of Wikipedia.
It is often a useful starting point
but you cannot trust it.
Linking to it is like linking to a Google search.
A starting point, not a destination.
highlight in red all
links to Wikipedia and Google search
and other possibly-unreliable user-generated content.