An illustration diagram displays a picture or image, along with labels that provide further information. Illustration diagrams can help explain complex ideas in a simple, engaging manner due to the strong use of visuals, narrative, and metaphor, and by breaking down complex concepts into small parts.
The image used can be in the form of a sketch, photograph, or a symbol or series of symbols. Certain areas can be enlarged to show greater detail, or can be shown as a cross section to show parts that would otherwise be hidden from view. Illustration diagrams are useful to explain the parts of an object such as the parts of machinery in an instruction manual for example, or to show how things work or explain concepts. These diagrams are commonly used in school to teach students scientific concepts such as parts of the human body, individual cells, flowers, or the solar system, for example.