* Solutions are homogeneous mixtures where the solute particles are completely dissolved and are very small (typically at the molecular or ionic level).

* Colloids have particles larger than those in solutions but smaller than those in suspensions. Think of milk, where tiny fat globules are dispersed throughout the liquid.

* Suspensions are heterogeneous mixtures where the particles are large enough to be visible and settle out over time. Think of sand in water.

In summary:

* Solutions: Smallest particles

* Colloids: Medium-sized particles

* Suspensions: Largest particles