1.5. Components of GIS

        A working GIS consists of six key components. These are hardware, software, data, people, methods, and network.  These components must be well integrated for effective use of GIS, and the development and integration of these components is an iterative, ongoing process.

Hardware
Hardware is the computer on which a GIS operates.  Today, GIS runs on a wide range of hardware types, from centralized computer servers to desktop computers used in standalone or networked configurations. However, a computer with good processing capability, large hard disk space, good-quality input and output devices, and fast network connectivity form the hardware foundation of GIS. While advances in computing technology during the past decades have substantially reduced the time required for most spatial analyses, computation times are still unacceptably long in personal computers. The hardware components that are specifically designed for use with spatial data include digitizers, scanners and plotters and printers.

Software

Software refers to the many free and commercial software packages that allow a GIS user to perform GIS function such as storage, manipulation, query, analysis, display, and effective dissemination of spatial information. The key software components include applications to input and manipulation of geographic information, a database management system (DBMS), applications to perform geographic query, analysis, and visualization, and a simple graphical user interface (GUI) for easy access to tools. There are many public domain and commercially available GIS software packages. While ArcGIS developed by the Environmental Systems Research Institute (ESRI) is an example of commercial software, QGIS and GRASS (Geographic Resource Analysis Support System) are examples for open source software. QGIS is an initiative under the Open Source Geospatial Foundation and the software is a collaborative effort by a community of developers and users worldwide. QGIS is free, stable, and the source code is available so that it can be extended as needed for specific tasks

Data

The most important component of a GIS is the data. It refers to any and all spatial and non-spatial information stored in a digital format on the computer. In GIS, data is stored as geographical data (spatial data) and related tabular data (non-spatial data). GIS integrates spatial and non-spatial data by using a Data base management System (DBMS). Even though data comes in various formats, GIS can ingest any type of data in many different types of formats.

Methods

To make a GIS system work properly requires not only the necessary investments in Hardware, software, and data but also requires the knowledge to utilize the GIS technology. Most GIS also require a set of protocols guiding how the GIS will be used. A successful GIS operates according to a well-designed plan and business rules, which are unique to each organization. Method in GIS includes how the data will be accessed, stored, managed, processed, analysed, and presented as output.

People

GIS technology is of limited value without the people who manage the system and develop plans for applying it to real world problems. GIS users range from technical specialists who design and maintain the system to general users such as Planners, Scientists, Engineers, and Decision Makers.

Network

Lastly, network refers to the computer network, either within an office or the internet. Both of these networks assist in the transfer and dissemination of data and applications. Data sharing in GIS is a quite common and useful operation. With the wide proliferation of sensors (data collectors), and well-established network, there is more data available to us today than ever before. Additionally, these networks allow for the display of information in the form of web maps, and web applications.

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