Which of the following is characteristic of a direct digital synthesizer (DDS)?

A Direct Digital Synthesizer (DDS) generates an analog waveform by calculating a time-varying signal in digital form and then converting it using a digital-to-analog converter. Because the digital timing is controlled by a master crystal oscillator, the resulting output frequency inherits the extreme stability of that crystal. Unlike traditional variable-frequency oscillators (VFOs) that rely on temperature-sensitive analog components and can drift over time, a DDS can digitally tune across a wide frequency range while remaining rock-solid. Distractors like 'pure sine wave output' are incorrect because DDS outputs inherently contain digital quantization noise and require low-pass filtering to clean up unwanted high-frequency artifacts.