The Network Analyst toolbox contains tools that perform network analysis and network dataset maintenance. With the tools in this toolbox, you can maintain network datasets that model transportation networks and perform route, closest facility, service area, origin-destination cost matrix, vehicle routing problem, and location-allocation network analyses on transportation networks. Use the tools in this toolbox whenever you want to perform an analysis on a transportation network.
The Analysis toolset contains tools used to perform analysis when using the ArcGIS Network Analyst extension. The toolset contains a variety of tools, including tools to create a network analysis layer and set its analysis properties for each solver provided with Network Analyst, tools to add network analysis objects to one or more network analysis classes, a tool to solve an analysis, and a tool to generate driving directions.
The Network Dataset toolset contains tools used to perform network dataset maintenance tasks such as building and dissolving network datasets.
The Turn Feature Class toolset contains tools used to build and edit turn data. The tools in the toolset allow you to create new turn feature classes, convert existing ArcView GIS or ArcInfo Workstation turn tables to turn feature classes, and maintain the integrity of existing turn features based on their geometry or an alternate ID field in cases when the reference source features are updated.
The tools within the Analysis toolset perform analyses using a network-based impedance such as travel time or distance. ArcGIS has other tools that can perform similar analyses but use straight-line distance or a raster cost surface.