DEFINITION: Grout cleaning is the process of removing dirt, grime, stains, and other debris from the grout lines between tiles or natural stone slabs. Grout is the material that is used to fill the spaces between tiles or stones to create a smooth, even surface. Over time, grout can become dirty, discolored, or stained, which can detract from the appearance of the tiled or stoned surface. Grout cleaning can help to restore the appearance of the surface and prevent further damage, such as water infiltration or shifting of the tiles.