How can mixtures differ?
There are a few types of mixtures.
Colloids, best tested for with the Tyndall Effect, are basically mixtures in which suspended particles will never settle out by themselves.
Suspensions are mixtures in which particles suspended will eventually settle out with time(eg. sand in water).
Homogeneous mixtures are mixtures in which you can not see different particles in one part of the mixture, as they are completely broken down and mixed evenly.
Heterogeneous mixtures are mixtures in which you can pick out particles of one substance from the other it is mixed with.