‘What is the Matrix? Control.’
We find Morpheus explaining this to Neo in the Construct; a blank, white space used by him and the Resistance to simulate any situation they require when training to take down the Agents.
He’s referring to the farming of human beings to provide power for a dominant race of robots – which we hope is a while off yet – but to look at the society we’ve built for ourselves, you can’t help but wonder if we’re lost in the green and black ether right now.
(Image from here)