Heterogeneous mixtures are those in which the components can be physically separated by filtration or some other physical means. For example, if sand and water are mixed, the sand can be separated from the water by filtration. The sand will be retained on the filter paper, while the water will pass through.

Homogeneous mixtures, on the other hand, are those in which the components are evenly distributed throughout the mixture and cannot be separated by physical means. For example, if salt is dissolved in water, the salt will evenly distribute itself throughout the water and cannot be separated by filtration or any other physical means.