3.3 Conveying information to others
Diagrams are used extensively in most types of texts, but why do authors use them? There are two main reasons:
to illustrate what something looks like;
to demonstrate how objects or ideas or quantities are organised or related.
However this is only one side of the situation, as such diagrams are usually intended to passively communicate models from one person to many (authors to readers). The main power in diagrams comes from an individual or group using them to actively further their own thinking. Although you need to do a lot of the former activity as a student or an employee, it is the latter activity that is central to much systems work.
But there is also a subsidiary reason I hinted at. Authors also use diagrams:
to decorate and enhance the text to make it more pleasing to read.