Derivative sub-genre of heavy metal, spear-headed by bands like Slayer and Lamb of God. Very aggressive guitar riffs, concrete-thick bass lines, ultrapresent drums and loud, abdominal-powered vocals mixed together in a fury that wakes the "homo neandertalis" sleeping in you. Lyrics consist mostly of all things unholy and forbidden to man, which is perfect for the musical support.
A quick reference? Hear Tom Araya scream "God hates us all!" at the top of his lungs... this is trash metal.