Vector
Polyline		A spatial file. Contains only polylines. Green= shapefile; Blue= feature class
Polygon		A spatial file. Contain only polygons. Green= shapefile; Blue= feature class
Point		A spatial file. Contains only points. Green= shapefile; Blue= feature class
Triangulated Irregular Network (TIN)		A vector representation of elevation over a landscape
Network Dataset		Network Datasets are used to create complex analysis of transportation networks utilizing detailed attributes regarding how each feature interacts with the others. Green= outside geodatabase; Black= inside geodatabase
Raster
Raster (Image file)		Any image file. May or may not be associated with spatial data. Yellow= outside geodatabase; Blue= inside geodatabase
Organization
Geodatabase		The biggest “container” for spatial data. Can contain vector or raster data.
Feature Dataset		A container for similar vector files. Can contain points, lines, or polygons (not rasters).
Raster Catalog		Collections of rasters which are organized and defined by a key. Can not contain vectors.
Topology		A GIS topology is a set of rules and behaviors that model how points, lines, and polygons share coincident geometry.
Tables
Excel Table		Excel table. Contains non-spatial data. Often is ‘joined’ or ‘related’ to spatial data.
Other Data Table (various kinds)		Tables without the specific .xls file extension. May contain non-spatial numeric or text data, or may contain numeric data associated with a spatial object. Tables are not specifically spatial, but often make up a crucial part of spatial data.
Other Icons
Text File		Text files are used for any sort of textual or paragraph data storage, such as metadata (information about the spatial data) or methods/other notes. While ArcGIS can read text files, they do not serve any sort of analysis purpose for us.