A world in which human bodies are used to provide energy to run the matrix (where do these bodies get their energy from isn't explained - presumably from the sun which is used to grow crops to feed the human bodies (but why not use sheep? - or just use the sun directly) - but then why would they need to develop a matrix?)
None of it made any sense.
But I enjoyed the first one and have seen it at least 10 times.
The original plot was that humans were used as processors (as a massive neural network). However, the director thought this would be too confusing for the average joe so they changed it to the whole battery thing.