A filter is a device or process that removes unwanted substances or elements from a mixture. In everyday life, filters are commonly used in water purification systems to eliminate impurities, ensuring safe drinking water. They can also be found in air conditioning units, where they trap dust and allergens, improving indoor air quality. In the digital world, filters are used in software applications to sort and manage data. For example, social media platforms like Instagram and Facebook allow users to apply filters to photos, enhancing their appearance. Similarly, search engines use filters to refine search results, helping users find relevant information more easily.