Definition - What does Screencast mean?
A screencast is a digital video recording of a user's screen or desktop complete with real-time or post-edited narration. It is often done as a video tutorial to allow viewers to follow exactly what the tutor/narrator is doing. It is related to the term screenshot, but whereas a screenshot is just a single image of the content of a computer screen, a screencast is a full video recording.
The term was originally selected by columnist John Udell from the suggestions provided by his blog readers whom he invited to propose a name for this upcoming genre. Screencast was suggested by Deeje Cooley and Joseph McDonald.
Techopedia explains Screencast
A screencast is basically a recording of what is happening on a user's screen as well as the user's narration. It is very useful for teaching and demonstrations or for integrating technology in educational systems. Other uses include software development and bug reporting, where testers can recreate the bugs in a recording and provide narration, replacing any potentially unclear written explanations.
With the growing popularity of YouTube as a media outlet, screencasting has become an important tool for providing demonstrations and tutorials such as how to use a certain software, play a musical instrument or even play games.
Screencasting requires the use of special software that can record the screen and user audio in real time. Another alternative is to use a dedicated screen-grabbing hardware such as a DVI frame grabber card. This approach can significantly reduce the load on resources for a machine that is already struggling to keep up with the video rendering, which is especially the case when screencasting games with high graphics settings.