Most solutions are a mixture of substances.  A solute is the dissolved substance is a solution.  A solvent is which the solvent in dissolved.  It is easy to know which is the solvent and which is the solute.  A rule of thumb to decide which is the solvent and which is the solute is the solute is the substance that changed phase.  If the substances were both in the same phase, then the substance that has the smaller amount is the solute.  An aqueous solution is when water is the solvent.  Popular solvents are carbon tetrachloride and benzene.  These are great for dissolving grease stains and spots (Dorin 334).