Filtration is a physical, biological, or chemical procedure that separates solid matter and fluid from a mixture with a filter medium with a complex formation through which only fluid can pass. Solid particles that cannot pass through the filtered method are described as being oversized, and the fluid that goes through is called the filtrate. Oversized particles may form a filter cake on top of the filter, which is identified as blinding.
The size of the largest fragments that can effectively pass through the filter is called the filter's effective pore size. The separation of solid and fluid is flawed, as solids will be contaminated with some fluid and filtrate will contain fine particles. Filtration arises both in nature and in engineered methods, and there are biological, geological, and industrial ways. Some examples of filtration include air filters, water filters, stone filters, and oil filters.