Data can be defined as "facts or figures from which conclusions can be inferred" (Webster's New World Dictionary, 1986). A definition for base is the "main part of a plan or system on which the rest depends" (Webster's New World Dictionary, 1986)". A definition for bank as it applies to a collection "is a row or tier of objects" (Webster's New World Dictionary, 1986)". A databank or database is often defined as "a large collection of data in a computer organized so that it can be expanded, updated, and retrieved rapidly for various uses"(Webster's New World Dictionary,1986)". In the past before computers were readily available, a database or databank was a box full of files or a file cabinet full of papers. Usually the information was filed with like objects together in some alpha numeric system that made sense to the user as a way to recall which items were together.
For example, if a butterfly collector had many different types of specimen from different continents, and they stored them in cabinets based on which continent they originated from, there would be an African cabinet, and Eurasian cabinet, an Australian cabinet, a North America and South America cabinet and so-on. In each cabinet they may further delineate the specimen by alphabetical order so that if they know the name, they know where in the cabinet the particular specimen they are looking for can be found. A database in general terms is anything that holds a collection of information of some sort.
Translated from the Greek the name geography meets to write about the land. A modern definition of geography " is the science dealing with the surface of the earth, its division into continents, and countries, and the climate, plants, animals, natural resources, people and industries of the various divisions"(Webster's New World Dictionary,1986). A geographic information system (GIS) is a relational database. One definition of relation is "a connection, as in thought and meaning" (Webster's New World Dictionary, 1986). So a relational database connects meanings of information. When we talk about geography we use maps to reference were all the action is taking place. A relational database having to deal with geography, naturally, uses maps to relate information about a particular place, climate, plants, animals, natural resources or people connected to the land. Often when you talk about a subject it can be isolated but often needs information about the environment it exists in so you can begin to understand how the environment has shaped the subject.
For instance, when you watch nature shows about lions, they can tell you specifics about the animal, like its height, its length, its weight and its scars, but in order to understand how it became this way you need to understand its environment. You need to know if it lives in the grasslands, or by mountains. You need to know if buffalo or antelope or giraffe are present as food sources and which it is most successful with. You need to know how many other large predators exist in proximity to the lion because this represents competition for the same food source. So these things although not specifically about the subject affect the data you are able to get directly from the subject.
A geographic information system allows people to look at this type of information and infer how these things mesh together to produce an outcome. In addition a GIS allows you to produce the representation of that data in visual form. So it is more than just a map with roads it is a connection with data and how that data affects, is effected by and changes with the land, its people, its animals and its natural resources. A GIS uses layers of information projected on top of one another to show how they affect on another in relation to space and time. A GIS studying a lion would have the base layer be a map of the land it lives on. Another layer would be a spread of where a prey like bison is located on that land, maybe even aerial photographs of where the animals are standing at the moment. Another layer might include any water features like rivers, ponds, lakes and creeks that draw prey into the lion's territory. Another layer might be the location of dens of competing predators. All this information would be visually meshed on top of one another in the computer. You then ask the database a question or a query about this information. Your query might ask the distance from the lion to the bison. You could also ask in that same query the distance from a water source also. So that you can try to infer from the map produced if the best hunting for this particular prey, is close to water sources within the lion's territory. In this way a GIS allows you to explore all the possibilities of how the environment affects the subject