# Review of Web Mapping: Eras, Trends and Directions
## 4 Trends and Directions in Web Mapping
### Trends in Web Map Usage Components
#### 4.1.3 Web Mapping Functionality Trends  
The breadth and complexity of functionality for geospatial data on the web has been developed extensively over the web mapping eras. What started with simple static maps as online images has developed into Web GIS systems with a full range of GIS functionality. [PERSON] and [PERSON] [124] identified three broad GIS functionality categories, namely: viewing, editing and analyzing. GIS software, including both desktop and web-based, provide functionality across all three categories, whereas other software including map viewers, mobile field map data capture, and basic web map clients may implement functionality across only one or two categories [124]. Initially, web mapping systems were focused on the viewing functionality, and with the development of supporting technology, expanded to include editing and, more recently, analytic functionality. In the static web mapping era, the focus of web mapping was primarily on viewing maps and providing some basic options for viewing. The Xerox Parc map [16] essentially provided users with a range of map images selected by choosing from some basic options for zooming, panning, coordinate systems and display layers using hyperlinks. The era of dynamic maps more closely represented map views that were more akin to those of GIS. The web mapping services era opened the way for map servers to provide not just map image services but also geospatial data and processing services. This enabled GIS functionality to be provided online, as was the case for MapQuest that implemented routing and navigation functionality with its online mapping [112]. Together with the developments during the Interactive and Collaborative web mapping eras, users were able to not only retrieve but also capture, edit, store and analyze geospatial data using asynchronous client/server technologies. The digital globe developments brought in tiled imagery into highly interactive 2D and 3D geo-browsers. While initially focused on viewing, the digital globe geo-browsers have been developed to include geospatial data editing, integration from various sources and basic GIS queries [125; 126; 127]. Examples related to advanced virtual globes include the analysis of Earthquake Signal Precursors [128], visualization and analysis of doxels data models [62], processing of satellite images for environmental analyses [83], and virtual high-speed railway 3D models [129]. The development of technologies such as CSS, AJAX and HTML enabled applications on web browsers to have the same functionality as those on desktop computers [130]. This, together with the cloud SAAS developments, has encouraged people to move from a desktop environment into the web environment using the Internet and cloud. They require access to similar functionality in a recognized and friendly environment tailored to their purpose of use. Examples of this include Google Docs on Google Drive and Microsoft Office on One-Drive, where documents are shared, edited and tracked in the cloud in real time among collaborators. The developments in cloud-based technology, providing the infrastructure to host both data and functionality online, brought rapid developments in web mapping as well as Web GIS. By implementing an architecture of web database and geoprocessing services in the cloud, a wider range of GIS functionality could be integrated within a true Web GIS online platform that became more accessible to a broader range of global users [131]. Cloud services provide functionality for everything from data sensor retrieval and information extraction to knowledge and ontology discovery; more and more data, information, and knowledge will be accessed by and serve functional web services online (Figure 8). The Web GIS environments currently have similar, although reduced, functionality and interfaces to the desktop GIS environments, although the distinctions are becoming less. There is a trend towards greater support, integration with and uptake of the online environment by GIS functionality.