Filterisation, often referred to as filtration, is a process used to separate solids from liquids or gases using a filter medium that allows the fluid to pass through while retaining the solid particles. This technique is commonly employed in various applications, including water purification, air filtration, and in laboratory settings. The effectiveness of filtration depends on factors such as the size of the filter pores, the nature of the materials being separated, and the flow rate of the fluid.