| Word | Description |
| QAM | Quadrature Amplitude Modulation. Method for modulating two carriers. The carriers can be analogue or digital. |
| QCIF | Quarter Common Intermediate Format. A videoconferencing format that specifies data rates of 30 frames per second (fps), with each frame containing 144 lines and 176 pixels per line. This is one fourth the resolution of Full CIF. QCIF support is required by the ITU H.261 videoconferencing standard. |
| Quad display | Equipment that simultaneously displays four images from four separate sources on a single monitor each occupying a quadrant of the screen. |