The document discusses cleaning solvents used in automotive shops. It defines solvents and solutions, and identifies common solvents like water, gasoline, kerosene, thinner, and detergent soap. It explains that solvents can be polar or non-polar based on their solubility in water. The document also provides steps for cleaning tools and work areas, including using the proper solvent and safety precautions. It gives examples of which solvents to use for different cleaning purposes like removing grease, paint, or cleaning upholstery.