To understand how we get from analog to digital maps, let us begin with the buil
To understand how we get from analog to digital maps, let us begin with the building blocks and foundations of the geographic information system (GIS) – namely, data and information. Geographic information systems stores, edits, processes, and presents data and information. However, what exactly is data? Moreover, what exactly is information? For many, the terms “data” and “information” refer to the same thing. For our purposes, it is useful to make a distinction between the two. Generally, data refer to facts, measurements, characteristics, or traits of an object of interest. For you grammar sticklers out there, note that “data” is the plural form of “datum.” For example, we can collect data about all kinds of things, like the length of rainbow trout in a Colorado stream, the number of vegetarians in Alaska, the diameter of mahogany tree trunks in the Brazilian rainforest, student scores on the last GIS midterm, the altitude of mountain peaks in Nepal, the depth of snow in the Austrian Alps, or the number of people who use public transportation to get to work in London.
Once data are put into context, used to answer questions, situated within analytical frameworks, or used to obtain insights, they become information. Information simply refers to the knowledge of value obtained through the collection, interpretation, and analysis of data. Though a computer is not necessary to collect, record, manipulate, process, or visualize data, or to process it into information, information technology can be of great help. For instance, computers can automate repetitive tasks, store data efficiently in terms of space and cost, and provide a range of tools for analyzing data from spreadsheets to GIS. An incredible amount of data is collected daily by satellites, grocery store product scanners, traffic sensors, temperature gauges, smartphone apps and endlessly more. This data would not be possible without the aid and innovation of information technology.
Geographic or spatial data refer to geographic facts, measurements, or characteristics of an object that permit us to define its location on the surface of the earth. Such data include, but are not restricted to, the latitude and longitude coordinates of points of interest, street addresses, postal codes, political boundaries, and even the names of places of interest. It is also important to note and reemphasize the difference between geographic data and attribute data. Geographic data is concerned with defining the location of an object of interest, attribute data is concerned with its nongeographic traits and characteristics.“Spatial data is information about the locations and shapes of geographic features and the relationship between them, usually stored as coordinates and topology.” – Esri
To illustrate the distinction between geographic and attribute data, think about your home where you grew up or where you currently live. Within the context of this discussion, we can associate both geographic and attribu