What are VOXEL graphics?

Could you please elaborate on what VOXEL graphics are? I've heard of them being mentioned in the context of gaming and 3D modeling, but I'm not entirely sure what they entail. Are they similar to voxel-based rendering, or do they have a unique distinction? Additionally, how do VOXEL graphics compare to other graphics techniques, such as polygon-based rendering or RAY tracing? I'm particularly interested in knowing the advantages and disadvantages of using VOXEL graphics in various applications.