Grout is a thick paste used to fill the gaps between tiles, providing a finished look to tiled surfaces. It is typically made from a mixture of water, cement, and sand, and can come in various colors to match or contrast with the tiles. Grout helps to secure the tiles in place and prevents moisture from seeping underneath, which can lead to mold and damage. There are two main types of grout: sanded and unsanded. Sanded grout contains fine sand, making it suitable for wider joints, while unsanded grout is smoother and ideal for narrow joints. Proper application and sealing of grout are essential for maintaining the integrity and appearance of tiled areas.