The term VRAM is used more specifically to describe a type of dual-ported RAM used in high performance raster graphics hardware. In a raster graphics system, the VRAM is called upon to constantly refresh the display, and at the same time be responsive to modifications from the host system. Dual Ported VRAM can provide data for the refresh system at the same time as allowing accesses from the host to modify data in that VRAM for higher performance.