Which separation technique you use depends on what kind of mixture you have. Filtration separates an insoluble solid from a liquid. The mixture is poured through filter paper. The liquid passes through the tiny holes and is called the filtrate. The solid is too big to pass through and stays on the paper as the residue. Sand and water is a mixture that can be separated this way.
Simple distillation separates a solvent from a solution, for example pure water from salt solution. The solution is heated in a flask until the water boils. The water vapour travels into a condenser, where it is cooled and turns back into liquid water, which is collected. The salt does not boil away, so it stays behind in the flask.
Fractional distillation separates a mixture of miscible liquids, which are liquids that mix completely, such as ethanol and water. Each liquid has a different boiling point. The mixture is heated and the vapours rise up a fractionating column. The liquid with the lowest boiling point reaches the top first and is cooled and collected. The liquid with the higher boiling point is collected later, or stays in the flask.
