“A screencast is a digital movie in which the setting is partly or wholly a computer screen, and in which audio narration describes the on-screen action. It’s not a new idea. The screencaster’s tools–for video capture, editing, and production of compressed files–have long been used to market software products, and to train people in the use of those products. What’s new is the emergence of a genre of documentary filmmaking that tells stories about software-based cultures like Wikipedia, del.icio.us, and content remixing. These uses of the medium, along with a new breed of lightweight software demonstrations, inspired the collaborative coining of a new term, screencast.” Link.
HOW TO – Screencasting