What is a simple definition of filtration?

A simple definition of filtration is the process of separating solid particles from a liquid or gas by passing the mixture through a material that blocks the solids but lets the fluid through. Think of it like using a strainer to drain pasta; the water goes through the holes, but the pasta stays in the strainer. In this analogy, the strainer is the filter, the pasta is the solid residue, and the water is the filtrate. Filtration is used everywhere, from making coffee to cleaning the air we breathe. It works because the holes in the filter are smaller than the solid particles but bigger than the liquid or gas molecules. This basic principle allows us to clean dirty water, remove dust from the air, and separate ingredients in cooking. It is one of the most common and important ways we keep things clean and safe in our daily lives.