
Broadly speaking, an effect can be any component of the picture or sound that is not a simple production element and is specially created to imitate a natural or unnatural event or otherwise produce some unusual response within the audience.
They can be a part of production (makeup effects, for example) or added later in post-production, as are many sound effects and visual effects (dissolves and fades, for example). Effects for both video and film can be grouped together into sound/audio effects and image effects.
Film Video Terms and Concepts Steven E. Browne, Focal Press, 1992
The National Film and Sound Archive of Australia acknowledges Australia’s Aboriginal and Torres Strait Islander peoples as the Traditional Custodians of the land on which we work and live and gives respect to their Elders both past and present.