The term electrolyte is often used to refer to a fluid which has ions (electrically charged molecules or atoms) dissolved in it such that it has electrical properties subject to electrolysis.
An electrolyte is a fluid which has been prepared for use in an electrolysis process. The source material is dissolved in an appropriate solvent (or melted) such that constituent ions are available in the solution.
Examples of electrolytes include acids and bases. The stronger the acid or base, the more electrolytic the substance will be. Salts are an example of strong electrolytes.