What is geoprocessing
Geoprocessing is for everyone that uses ArcGIS. Whether you're a new or advanced user, geoprocessing is likely an essential part of your day-to-day work with ArcGIS. The fundamental purpose of geoprocessing is to provide tools and a framework for performing analysis and managing your geographic data. The modeling and analysis capabilities geoprocessing provides make ArcGIS a complete geographic information system.
Geoprocessing provides a large suite of tools for performing GIS tasks that range from simple buffers and polygon overlays to complex regression analysis and image classification. The kinds of tasks to be automated can be mundane—for example, to wrangle herds of data from one format to another. Or the tasks can be quite creative, using a sequence of operations to model and analyze complex spatial relationships—for example, calculating optimum paths through a transportation network, predicting the path of wildfire, analyzing and finding patterns in crime locations, predicting which areas are prone to landslides, or predicting flooding effects of a storm event.
Geoprocessing is based on a framework of data transformation. A typical geoprocessing tool performs an operation on an ArcGIS dataset (such as a feature class, raster, or table) and produces a new dataset as the result of the tool. Each geoprocessing tool performs a small yet essential operation on geographic data.
Geoprocessing allows you to chain together sequences of tools, feeding the output of one tool into another, as illustrated in the examples below. You can use this ability to compose an infinite number of geoprocessing models (tool sequences) that help you automate your work and solve complex problems. You can share your work with others by packaging your workflow into an easily shared geoprocessing package. You can also create web services from your geoprocessing workflows.
Sharing your workflows
Geoprocessing models you create, and the data that they use, can be shared using geoprocessing packages. The package you create can be e-mailed to your colleagues or uploaded to arcgis.com where they can reach a broad audience. You can also create and publish web services from your models to be consumed by web-based clients such as ArcGIS for Desktop, ArcGIS Explorer, and custom web applications.
Developing your own tools
You can create your own tools using ModelBuilder or Python. Tools you create are called custom tools and become an integral part of geoprocessing, just like system tools (those installed with ArcGIS Desktop). You can open and run your tools from the Search, Catalog, or ArcToolbox window, use them in ModelBuilder and the Python window, call them from another script, or add them as toolbar buttons.