I watched the movie a few weeks ago and still didn’t get the ending. I had guesses to what was going on, but I wasn’t going to read through all the third-party explanations, especially when the book still is available.
What a treat!
The movie followed the book closely, but the movie ending pales in comparison to what was written. It’s like comparing a saltine cracker to a thick, juicy, well-seasoned grilled Ribeye.
It was also one of the most impressive treatments of a continuing consciousness I’ve read.
I did wonder why the destination in the movie was changed but it was explained in the epilogue. Without something like today’s CGI, they couldn’t replicate the splendor of Saturn rings that Clarke so effectively wrote about, so they opted for Jupiter instead.
https://ia800800.us.archive.org/7/items/SpaceOdyssey_819/2001_A_Space_Odyssey_-_Arthur_C_Clarke.pdf