Signal processing is the processing, amplification and interpretation of signals. Signals may come from various sources. There are various sorts of signal processing, depending on the nature of the signal, as in the following examples.

• Digital signal processing - for signals that have been digitized. Processing is done by digital circuits, microprocessors or computers.
• Analog signal processing - for signals that have not been digitized
• Audio signal processing - for electrical signals representing sound
• Speech signal processing - for interpreting spoken words
• Video signal processing - for interpreting moving pictures
• Array processing

Topics in signal processing:

• Quantization (signal processing)
• Anti-aliasing