Easiest answer to that is, read the book. It pretty much explains everything. If I were to give a short and unsatisfactory explanation, as humans we're ill-equipped to handle the immensity of the universe, and our machines are overtaking our ability to run our own civilization. So Dave is propelled to the next level of evolution, whatever that may be. And that's a terrible, terrible explanation that doesn't begin to explore the concepts. To put it more succinctly, I think the movie is an exploration of man's relationship with his machines. And aliens' relationship with their machines. Basically the role that technology plays in the evolution of intelligent life.
Easiest answer to that is, read the book. It pretty much explains everything. If I were to give a short and unsatisfactory explanation, as humans we're ill-equipped to handle the immensity of the universe, and our machines are overtaking our ability to run our own civilization. So Dave is propelled to the next level of evolution, whatever that may be. And that's a terrible, terrible explanation that doesn't begin to explore the concepts. To put it more succinctly, I think the movie is an exploration of man's relationship with his machines. And aliens' relationship with their machines. Basically the role that technology plays in the evolution of intelligent life.