This Chapter embraces a very broad range of tools and techniques, many of which are now incorporated into all modern GIS software packages. Indeed, many form part of the basic set of facilities that must be provided if the GIS software is to be compliant with the Open Geospatial Consortium's (OGC) specifications. Even if a product is not listed by the OGC as compliant it may be partially or fully compliant but simply has not been submitted to them for testing.
Initially we explain the basic geometric, querying and distance-based operations that form part of the building blocks for GIS software. These operations are often referred to as spatial analysis by the software providers, but are in reality little more than the essential components of a usable spatial data handling system. A number of operations, notably those relating to directional analysis and some grid-based operations, are provided in a subset of GIS software packages, but may still be regarded as core building blocks of spatial analysis.