A map is an abstract representation of the physical features of a portion of the Earth's (or some other planet's) surface graphically displayed on a planar surface (generally, a sheet of paper). Maps display signs, symbols, and spatial relationships among the features. They typically emphasize some features, generalize others, and omit certain features from the display to meet design objectives. (Adapted from Pennsylvania Spatial Data Access (PASDA)'s ArcView Tutorial glossary.)
Scale is defined as the ratio of the distance on the map to the distance on the ground.
What is considered large scale and what is considered small scale?
For more information on map scales, see the USGS factsheet on Map Scales.
The latitude of a point is defined as the elevation angle of that point above or below the equator.
On the globe, lines of constant longitude ("meridians") extend from pole to pole, like the segment boundaries on a peeled orange. The longitude of a point is defined as the marked value of that division where its meridian meets the equator.
NASA provides an explanation of latitude and longitude with diagrams.
In 1785 the Continental Congress adopted legislation that laid down the system for surveying the lands of the West. A public land survey divided and subdivided the United States into squares that could then be mapped and sold. This grid system covers the entire United States, except for the original 13 states, and is still used today to specify locations. This system is commonly called Township and Range.
Please consult the following resources for more details: