What function does a filter serve in signal processing?

A filter in signal processing operates primarily by removing unwanted components or features from a signal. This is a crucial function because real-world signals often contain noise or interference that can distort the information being transmitted or processed. By applying a filter, specific frequencies can be attenuated or eliminated, allowing the desired signal to be emphasized.

For example, a low-pass filter allows signals with a frequency lower than a certain cutoff frequency to pass through while attenuating frequencies higher than this cutoff. This is particularly useful in situations where high-frequency noise interferes with the signal of interest.

The other options involve different functions: amplifying a signal (which is done by amplifiers rather than filters), converting analog signals to digital (a function performed by analog-to-digital converters), and storing signals (which relates to memory systems or storage devices). Each of these functions is important in signal processing, but they do not directly relate to the filtering process.