Goo, commonly known as slime, is a viscous, stretchy substance that is often made from a combination of polyvinyl alcohol and borax. It can also be created using household ingredients like glue and water. Goo is popular among children for its fun, tactile properties and is often used in sensory play. There are many variations of goo, including glitter slime, fluffy slime, and magnetic slime, each offering unique textures and visual effects. It can be colored with food coloring or paint and is often used in arts and crafts. Goo is safe to play with, but it should not be ingested.