Read Unit 1, Lessons 1-3 for next time. Multimedia computing is the combined use of more than one digitized media in an interactive format. Text is a medium. Sound is a medium.
Graphics are a medium.
Animation is a medium. And video is a medium. Texts, sound, graphics, animation, and video are media. In fact, they are the media that are most often meant when we speak of multimedia. Also, although a program with text, sound, graphics, and animation might fit both of the above definitions, video is often considered to be the defining feature of multimedia.