To answer your subquestion what characterises a software as a GIS type, the following definition freely adapted from wikipedia seems to define the term quite well. A geographic information system (GIS) is a system designed to capture, store, manipulate, analyse, manage, and present all types of spatial or geographical data. It is thus a quite broad term that describes any information system that integrates, stores, edits, analyses, shares, and displays geographic information. Examples of GIS applications are tools that allow users to create interactive queries, analyse spatial information, edit data in maps, and present the results of all these operations.