A solvent is a substance that does the dissolving. For instance, water is a solvent. You can dissolve different things in it. They usually dissolve with a solute to form a solution. Different solvents dissolve different things. For instance, water cannot dissolve oil. However, alcohol can easily dissolve oil. This makes solvents different from each other.
Each has its particular properties that makes it different from other solvents. Because of this, different solvents have different applications and uses. They allow users to dissolve different things and serve a variety of purposes. They are often used to dissolve stains or to mix two liquids that do not mix.