A more thorough explanation:

Definition: An audiovisual work is a type of work that consists of related images presented in a series, usually with the aid of a machine, and accompanied by sound. It is an original expression in fixed or tangible form that may be entitled to common-law or statutory copyright protection. Examples of audiovisual works include lectures illustrated with a filmstrip or a movie with a soundtrack.

Example: A documentary film about climate change is an example of an audiovisual work. It consists of a series of related images, such as footage of melting glaciers and rising sea levels, presented with the aid of a machine, such as a projector or a television, and accompanied by sound, such as narration or music. The film is an original expression in fixed or tangible form that may be entitled to copyright protection.

Explanation: The example illustrates the definition of an audiovisual work by showing how it consists of related images presented in a series with sound. The documentary film about climate change is an original expression that may be entitled to copyright protection because it is an audiovisual work.