* Solution: A solution is a homogeneous mixture where one substance (the solute) is dissolved completely into another substance (the solvent).
* Colloid: A colloid is a heterogeneous mixture where particles of one substance are dispersed throughout another but are not dissolved.
Nail polish remover typically consists of a solvent like acetone or ethyl acetate, and sometimes other ingredients like oils or moisturizers. The solvent dissolves the nail polish, creating a homogeneous mixture. Since there are no visible particles suspended in the remover, it's classified as a solution.