Mixtures are variable, and can be separated more easily than compounds, using purely physical means such as filtration, flotation, magnetism or distillation.
Mixtures are more variable than compounds. The parts can be separated more easily using purely physical methods like filtration, flotation and distillation.
A solution is a mixture made up of a solute (the thing dissolved) and a solvent (the thing dissolving). A solute and solvent cannot be separated by filtration.
An emulsion is a mixture in which the particles are too large and discrete for it to be regarded as a solution, but which are fairly well mixed together.