| Word | Description |
| S-VHS (Super VideoHome System) | Format on high resolution VHS video recorders, capable of giving greatly improved picture if all features are used. VHS compatible. |
| S.E.C.AM. (Systeme Electronique Couleur Avec Memoire. See CCIR) | Colour TV system used in France. |
| S/N Ratio (Signal to Noise Ratio) | Measure of noise levels of a video signal; the higher the number the better. |
| SCART | SCART is derived from 'Syndicat des Constructeurs d'Appareils Radiorécepteurs et Téléviseurs'. It is a Standard European 21 pin connector used for carrying both video and audio signals in various Video and Audio appliances. |
| Single-Mode Fibre | An optical fibre that supports only one mode of light propagation above the cut off wavelength. The core diameters are usually between 5 and 10 micrometres (um). |
| SS | Spatial Sensitivity. This generally sets the amount of space required by an object to activate an event. |