"A storyboard is a low fidelity prototype consisting of a series of screen sketches. They are used by designers to illustrate and organize their ideas and obtain feedback. They are particularly useful for multi-media presentations."
"A storyboard is a short graphical depiction of a narrative. Storyboards can be used for a variety of activities. In designing new technologies, storyboards often illustrate an envisioned scenario of how an application feature works." (Truong, Hayes & Abowd 2006)
"The storyboard is a tool derived from the cinematographic tradition; it is the representation of use cases through a series of drawings or pictures, put together in a narrative sequence."
We've collected some example storyboards.
Truong, K. N.; Hayes, G. R. & Abowd, G. D. (2006), 'Storyboarding: an empirical determination of best practices and effective guidelines' 'Proceedings of the 6th conference on Designing Interactive systems' , ACM , 12-21 http://www.mrl.nott.ac.uk/~axc/G64UID/Papers/Storyboards.pdf
Storyboarding template (use the template)