A filter, often referred to as a strainer, is a device used to separate solid particles from liquids or gases. It typically consists of a mesh or porous material that allows the fluid to pass through while trapping larger particles. Filters are commonly used in various applications, including cooking, water purification, and industrial processes. In the kitchen, a strainer can help remove food particles from liquids, such as when draining pasta or making broth. In industrial settings, filters are essential for maintaining equipment efficiency and ensuring product quality by removing contaminants from fluids, such as in oil filtration or air purification.