Audiovisual (AV) means possessing both a sound and a visual component, such as slide-tape presentations, films, television programs, church services and live theater productions. Business presentations are also often audiovisual. In a typical presentation, the presenter provides the audio by speaking, and supplements it with a series of images projected onto a screen, either from a slide projector, or from a computer connected to a projector using presentation software. Computer-based audiovisual equipment is often used in education, with many schools and universities installing projection equipment and using interactive whiteboard technology. Another audiovisual expression is the visual presentation of sound (visual music).