What is the difference between an arbitrary waveform generator and a function generator?

The Function Generator provides a preset list of waveforms or code patterns that it can generate. In a function generator, the user can change waveform parameters such as frequency, amplitude, and offset, as well as add simple distortion. Arbitrary waveform generators are more complex and can emulate real-world signals. Arbitrary waveform generators generate these waveforms using pre-stored digital data that describes the changing voltages of the signal. Typically, arbitrary waveform generators produce customized waveforms that are compiled rather than common waveforms that are preset.