An overview of Web GIS

A common task that you will perform as an ArcGIS user is to design and author GIS maps for use by others in (and perhaps outside) your organization. You will publish those maps using a range of GIS servers and applications, and your end users will utilize these maps to address any number of questions, missions, and problems.

This help section provides an overview for this map authoring task and a guide for designing and creating effective maps using ArcGIS. One of the primary focuses of this section is to provide guidance on how to build maps that are deployed on the Web using ArcGIS Server.

Comparing printed maps and computer maps

A printed map is a visual representation of an area organized as geographic features, symbols, and descriptive text onto a page. The primary map element is the map frame, and it provides the principal display of geographic information. Within the map frame, geographic entities are presented as a series of map layers that cover a given map extent—for example, map layers such as roads, rivers, place-names, buildings, political boundaries, surface elevation, and satellite imagery. Most maps are two-dimensional, but 3D representations are also often used.

Electronic or digital maps are maps that are displayed and used on a computer. There are various kinds of digital maps. The simplest are map pictures or photographs that present geographic views of an area of interest. For example, here is an extract from a digital map picture of a USGS Digital Raster Graphic (DRG):

A portion of a USGS digital raster graphic (DRG), which was created by scanning and georeferencing the USGS paper 1:24,000-scale topographic map series for the United States

These simple map types can be georeferenced so that they can be overlaid with other map information. This also enables you to pan, zoom, and navigate around the map to view various areas. The map, however, is still a relatively simple view (albeit often containing exquisite cartography). It's just a picture. Users often overlay (or "mash up") their own digital information on these types of computer maps.

GIS systems can be used to create both of these types of maps. Yet another type of map exists that enables you to use this map view to access further information about the features in the map. These more intelligent maps provide a window into rich geographic information for an area. Because they are interactive, they can also include a series of tools or operators that allows you to access and work with geographic information. We refer to this as a GIS map.

GIS maps

Like these other map types, GIS maps provide a visual representation of geography, but they also provide two additional and very important capabilities:

Each GIS map combines the power of visualization with a strong analytic and modeling framework that is rooted in the science of geography. It's this ability to tap into rich GIS databases and sophisticated spatial operators that enables each GIS map to address a range of problems and needs.

As an ArcGIS user, one common task is authoring and publishing GIS maps for use by people in your organization. These GIS maps help your users perform their daily work, visualize situations and issues, understand and gain insight, and communicate more effectively.

Characteristics of GIS maps

GIS maps provide a powerful metaphor to define and standardize how people use and interact with geographic information. GIS maps provide the primary user interface for most GIS applications. Users can point to map features to display information about them, discover new relationships, perform editing and analysis, and efficiently communicate results using geographic views such as interactive 2D maps, 3D scenes, and 3D globes.

You can think of each GIS map as an interactive computer application that you access and use on a computer or a mobile device. The GIS map provides a user interface to GIS. Each GIS map application contains a map view plus tools and operators to work with the map's contents. Here are some key characteristics of these GIS maps: