»How does The Matrix Movie related to Philosophy?«

My professor today explained how The Matrix movie was relevant to the external world whether we believe it or are unaware of. I have watched the movie years ago and don't quite remember it, all I remember is that Neo consumes a red pill and wakes up in this slimy scary looking pod...May anybody please explain with great detail?..whether if it's knowledge related, brain in the vat, beliefs, reality?