Electrical signals can be used to characterize a variety of physical occurrences. These signals rarely provide insight in their raw nature due to the addition of noise and other factors. Signal processing involves converting these signals from their raw state to a more useful form.
Signal processing includes both analog and digital signal processing. In analog signal processing traditional analog circuitry mostly comprising of operational amplifiers are used to process signals. Digital signal processing takes advantage of the vast improvements in computing to process signals in a computer or a DSP (digital signal processor).
Signal processing is extensively utilized in a lot of applications including radio communications, audio signal processing, image processing, video processing and many others. Signal processing plays an important role in our daily lives; from making a phone call to listening to music. Other uses are found in oil exploration, radar and sonar, and medical imaging. Software applications like Google Now and Siri employ signal processing to analyze and understand human speech (voice recognition)