A solvent is a substance, usually a liquid, that dissolves a solute, resulting in a solution. The most common solvent is water, often referred to as the "universal solvent" because it can dissolve many substances. Solvents are essential in various applications, including chemical reactions, cleaning processes, and the formulation of products like paints and pharmaceuticals. In chemistry, solvents can be classified as polar or nonpolar, depending on their molecular structure. Polar solvents, such as water and ethanol, have molecules with a positive and negative end, allowing them to interact with other polar substances. Nonpolar solvents, like hexane, do not have charged ends and are better at dissolving nonpolar compounds, such as oils and fats.