* Solution: A solution is a homogeneous mixture where one substance (the solute) dissolves completely into another substance (the solvent). Distilled water is essentially pure water, meaning it contains no dissolved substances.

* Colloid: A colloid is a heterogeneous mixture where particles are dispersed throughout a medium but are larger than those in a solution. The particles in a colloid are large enough to scatter light (Tyndall effect), but not large enough to settle out. Distilled water doesn't have these dispersed particles.

* Suspension: A suspension is a heterogeneous mixture where particles are large enough to settle out over time. Distilled water doesn't have any particles that would settle out.

In summary: Distilled water is a pure substance, not a mixture, so it doesn't fit into any of these categories.