The graphics address remapping table (GART), sometimes known as the graphics translation table (GTT), is an I/O memory management unit (IOMMU) used by AGP and PCI Express graphics cards. The GART allows the graphics card direct memory access to the host system memory, through which buffers of textures, polygon meshes and other data are loaded. It's used as a means of data transfer between physical memory and video memory, but can also be used to expand the amount of video memory available for graphics cards -- particularly for cards with no dedicated video memory, such as Intel integrated graphics.