The Matrix was the brilliant construction and engineering feat of the unified race of machines that solved man's infinite hunger for the Earth's finite resources. Rather than occupying real space on the Earth's surface; burning real fossil fuels exumed from within the Earth's crust; decimating real rain forests that once populated nearly all of the land mass of the planet, man has been reborn in a simulation. On a side note: the human body is not really the most efficient / abundant dynamo available to the machine race for transforming biochemical energy into heat and electricity, but this is what the machines would like us to believe, in order to maintain man's perception of the machine race as one of "pure horrifying precision," against which (and this is the key) a war is completely futile. The sooner you accept your new reality, the happier you will become.
In the film "The Matrix," the machines offered Cypher a grand life, even as his human "companions" took it from him!