Heterogenous mixtures do not appear to be the same throughout. Concrete, conglomerate rock, as well as oil and vinegar are all heterogeneous mixtures. The particles are large enough to be seen and can be separated from the mixture. The following are examples of mixtures. Homogeneous mixtures are very well mixed.
Solutions are homogeneous mixtures.
In a solution one substance is dissolved in another. The particles in a solution are atoms, ions, or molecules. The particles are obviously too small to be seen and will not separate out on standing. Solutions have two parts. Water is often called the universal solvent because it dissolves so many materials.