The mixture is composed of two or more substances that can be present in varying amounts and can be physically separated by using methods that use physical properties to separate the components of the mixture. The appropriate method to use for separating the components in a mixture depends on the physical states. Separations exploit differences in chemical properties or their physical properties. For instance, size, shape, mass, density, or chemical affinity between the constituents of a mixture. Some of the common methods of the separation are filtration, evaporation, distillation, sedimentation and decantation, magnetic separation, centrifugation.
A solution is a mixture that consists of a solute and a solvent. The solute is a solid that is dissolved in the solvent (which is a liquid) and together they make up a solution. Ask yourself, in a brine solution consisting of salt and water, which is the solute and which is the solvent?
The idea behind the separation techniques of mixtures is to separate the solute and the solvent from each other as they may be much more useful independently. Like in the example above, we separated gold from the dirt and the gold was useful for us.