GIS is the automated acquisition, management, analysis and display of spatial data. Perhaps the reason that no one has come up with an all encompassing definition of GIS is because it is not a single process. Rather, a GIS is more like a network of processes working together. Each feature is linked to a geographic position. Non geographers prefer to use 'spatial' or 'land' instead of 'geographic'.
Information can mean many different things.
Land Information Systems. Geographic Information Processing Systems. However, we can ask a GIS the same question and it will show where the query is true. Forest attributes or municipal ownership. Give an example of a query that a GIS can answer which a mapping package cannot.