Network diagrams are often drawn using software-based drawing tools, Figure 1 was drawn using Microsoft Visio, although there is nothing stopping you from using simpler tools such as whiteboards. Hand-drawn network diagrams are often used as the starting point for either a clean network diagram created with a drawing tool or a more detailed UML deployment diagram.
The scope of a network diagram can be either a single application, a family of applications, or even your entire enterprise. An enterprise network diagram is often used as the starting point, when available, for either an application-level network diagram or UML deployment diagram. A combination of a network diagram and installation script is often used as an alternative to a detailed UML deployment diagram.
This artifact description is excerpted from Chapter 10 of The Object Primer 3rd Edition: Agile Model Driven Development with UML 2.