What is filters?

Filters, in a broad technological sense, are components or processes that selectively allow certain inputs or aspects of an input to pass through while blocking others. They are used in a wide variety of applications to refine, isolate, or modify signals, substances, or other forms of input. Examples include image filters in photo editing software, signal filters in audio processing, and physical filters that remove impurities from liquids or gases. They operate by applying specific criteria or rules to the input, such as frequency, color, size, or chemical properties, and selectively allowing components that meet those criteria to proceed while rejecting those that do not.