Understanding millimeter-wave (mmWave) concepts can benefit RF designers, high-speed digital circuit designers and fabricators. In the RF industry, as frequency increases many circuit properties become increasingly difficult to control. Circuits used at mmWave frequencies (above 30GHz) have smaller wavelengths. Due to this small wavelength, circuit performance can be affected by very small circuit anomalies that in the past could have been ignored at lower frequencies. These small circuit anomalies can be caused by a variety of issues, such as normal variations of several processes for PCB fabrication, circuit designs being sensitive to the anomalies and normal variation of certain high-frequency material properties. This presentation will give a basic overview of what to consider in order to optimize the circuit performance at mmWave frequencies. For high-speed digital circuits, the presentation will include information on how mmWave concepts can be used to optimize high-speed digital circuits as the Nyquist frequencies approach the RF mmWave frequencies.