Space can be classed as a vacuum, "Void of matter".
Of course experiments with vacuums have proven something that originally seemed odd.
When you remove matter, you would think at first that all risidule energy is also removed (and light).
Within a manmade vacuum even with all matter removed exists Zero-point energy. This is the energy which is classed as the universe background noise and the energy is present in space, and the volume occupied by mass.
Notice I say volume, this means that something occupies a space, but it's no longer classed as space as it takes up a specific volume (Or space is no longer void of matter).
what exactly is Zero-Point Energy?
Well I have an idea that might be similar to other peoples theories or could be completely wrong.
Some would speculate that a background sound is like the noise the universe had laid down in the shockwaves of the big bang.
My understanding points to the fact that atoms give off a decay state, Psi wave (Would be the Greek symbol for Psi or a fork like symbol)
This means that although people comprehend all that quanta of an atom conforming to some gravity through it's interactions (Namely an electron spins around a Nuclei), an amount of energy is emmitted that extends beyond the atoms gravity, creating a kind of cloud of energy around it.
This cloud is what allows differing atoms to bond, as it isn't just an energy trace, but it also has some of the magnetic properties that cause a gravity (and bond).
There is also a point that when looking at Quantum mechanics, it can be found that a matrix of wave formations can cause patterns of raises and lulls, this can cause Spacetime distortions, and move some of the Psi wave through something called Non-Locality to the opposite side of one of these matrix raises of lulls.
(Non-Locality is like walking away from or to a mirror that mirrors things on it's horizontal and vertical axis. This means that your Left doesn't just become your right, but your down becomes your up (when looking in the mirror)
there is the assumption that such a mirror could occur within the universe, and although your right here and your right there would be the same from your perspective, if they met, it would be a Matter/Anti-matter collision.
So I would say "Space is void of matter" but "A vacuum isn't void of energy" and between those statements you should be able to get an idea.