A slidecast is an audio podcast that is combined with a slideshow or diaporama presentation, or just a live slideshow without audio. It is similar to a video podcast in that it combines dynamically-generated imagery with audio synchronization, but it is different in that it uses presentation software, such as PowerPoint, to create the imagery and the sequence of display separately from the time of the audio podcast's original recording.
Slidecasting may be useful for the display of relevant photographs or text, and are an alternative to camera video recordings.
An alternative definition of the slidecast is the online distribution and syndication of video recordings of live slideshow presentations and accompanying narrations.
Like other podcast derivatives, slidecasts are syndicated through RSS. Because of the visual dependency, slidecasts are usually distributed in video formats, such as .flv or .mov, similarly to video podcasts, but HTML 5 now makes it possible for slidecasts to be distributed in straight HTML, making them compatible with iPhone and iPad devices. Slidecasts may also be embedded into webpages and textual blog articles in a similar fashion to web-based videos