A simple solution is basically two substances that are evenly mixed together, but the mixture is homogeneous. Meaning, you can no longer tell the two substances apart once they are mixed in solution.
This is because the solute dissolves in the solution.
A solute is the substance to be dissolved (sugar).
The solvent is the one doing the dissolving (water).
As a rule of thumb, there is usually more solvent than solute.The amount of solute that can be dissolved by the solvent is defined as solubility.