A diagram is a representation of geographic information drawn with symbology.
Schematics, sometimes called schematic diagrams, are diagrams that show simplified representations of networks. These diagrams explain the network structure and the way it operates. They are often used to represent networks in a defined space without scaling constraints. For example, a defined space is a piece of paper where numerous pieces of information are displayed by optimizing the placement of the features. In schematics, there are no scale constraints (cable length, distances, and so forth).
The utility network and trace network provide an integrated mechanism for working with diagrams. That is, when a utility network or trace network is created, diagram data model tables and default diagram templates are also created by default. Network diagrams allow you to efficiently create multilevel representations, readily check network connectivity, and obtain logical views of any utility network or trace network.
A utility network or trace network created in a geodatabase contains preconfigured schematic diagramming capabilities that allow you to generate diagrams from the network without specific configurations.
You can also build your own schematic diagramming models or import models that were built for another utility network or trace network.