The ArcGIS Network Analyst extension allows you to perform transportation network analysis, such as vehicle routing, on a network dataset.
To learn more about working with Network Analyst, see the Transportation network roadmap.
See Also:
What is Network Analyst?About the Network Analyst Tutorial
Essential Network Analyst vocabulary
NetworkAnalyst
Network Analyst Object Model diagram
Network Analyst UI Object Model diagram
An overview of the Network Analyst toolbox
What is a network dataset?
How to open a network dataset
Programming with Network Analyst