"A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data."
An introduction to GIS, including the principles of spatial data management, spatial analysis, and geospatial modeling.
"[A GIS] consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data."
"Much of this often happens within a spatial database, however, this is not essential to meet the definition of a GIS."
"One may consider such a system also to include human users and support staff, procedures and workflows, the body of knowledge of relevant concepts and methods, and institutional organizations."
"The uncounted plural, geographic information systems, also abbreviated GIS, is the most common term for the industry and profession concerned with these systems."
"The academic discipline that studies these systems and their underlying geographic principles, may also be abbreviated as GIS, but the unambiguous GIScience is more common."
"They are attached to various operations and numerous applications, that relate to: engineering, planning, management, transport/logistics, insurance, telecommunications, and business."
"GIS and location intelligence applications are at the foundation of location-enabled services, which rely on geographic analysis and visualization."
"GIS provides the capability to relate previously unrelated information, through the use of location as the 'key index variable'."
"Locations and extents that are found in the Earth's spacetime are able to be recorded through the date and time of occurrence, along with x, y, and z coordinates."
"[x, y, and z coordinates representing] longitude (x), latitude (y), and elevation (z)."
"All Earth-based, spatial-temporal, location and extent references should be relatable to one another, and ultimately, to a 'real' physical location or extent."
"This key characteristic of GIS has begun to open new avenues of scientific inquiry and studies." Note: Since not all 20 questions can be answered directly by quotes from the paragraph, I have provided answers for the available quotes.