When scientists claim that a substance is soluble, they mean that it can be dissolved, most commonly in water. For example, sodium chloride (ordinary table salt) is soluble in water.
Solvents and Solutes
In order for a material to be dissolved, there must be a solvent to dissolve it. The solvent in a solution is greater in quantity than the solute. When it is added to the solvent, the solute will have its molecular bonds broken before combining with the solvent.
A solvent can only dissolve so much solute. A solution is unsaturated if you can keep dissolving more solute, whereas it is saturated when the solvent can dissolve no more solute. A supersaturated solution can exist when the solution is heated up to dissolve more solute, increasing the solubility of the solute, then lowering the temperature of the solution.
Solutions are part of everyday life. Coffee is a solution of coffee grounds and water. Automotive antifreeze is mixed with water. Even mixed drinks from the bar are examples of solutions. Nearly every drink is a mixture of two or more liquids, or a liquid and a solid.