The above image was created using ArcExplorer 2.0.

This image depicts the area southeast of Elizabethtown, PA in Lancaster County. The geocoded location is my parents' house in Mount Joy Township, which is in Elizabethtown, PA.  The straight road to the northeast is state route 283, the four-lane highway that connects Lancaster and Harrisburg and has two exits in Elizabethtown.  Just west of my house is Campus Road, which continues to the west for a mile to the Elizabethtown College campus.  Most of the empty land to the left and right of my address is acres and acres of farmland.  There is a quarry and a pond to the northwest but this particular data does not show hydrography.

In order to better associate the data the Census Bureau received from census forms with geographic location, they created the TIGER (Topologically Integrated Geographic Encoding and Referencing) Database. TIGER files are digital representations of geographic features such as landmarks, roads and districts. They are made into maps by corresponding dots, lines and polygons with landmarks, roads and districts.
The TIGER database supports the Census Bureau’s operations in three ways. First, census takers used to have to visit households in person and then they handwrote address information on a map. However, address data is now matched to geographic data automatically using TIGER data, eliminating the need for so many visits. Second, the Census Bureau gets consistent maps from these TIGER/line files that have the same scale; this aids census takers in getting around. Finally, it gives the Census Bureau a commercial product to make available to constituents in the form of maps and atlases.
TIGER/line data is also available to the public just as it was to us for this project. For instance, it can be used to aid emergency response teams and make their operations more efficient by creating clearer, more accurate maps to improve response times.  It can also be used by city councils and researchers to associate demographic trends and other attribute data with specific neighborhoods or areas.