L-GIS Glossary,

This glossary is a sub-set of one developed by the Urban and Regional Information
Systems Association (URISA)

Labels
Labels are text posted on a map near a spatial feature. The source of the text typically is Either a linked database record or a text element created by at the location by the cartographer.

Layer
This term refers to a logical grouping of map features to be viewed individually or in combination. This concept is similar to one using transparent acetate overlays of different map features to add or remove visible map features. This term also means a distinct set of spatial features that are dealt with together.

Legend
A legend is an explanation of the symbols, codes, names given variables and other information appearing on a map drawing or chart. Legends include a sample of each symbol, line pattern, shading, or hatching appearing on the map along with annotations describing the meaning of each.

Lookup Table

• Database table that assigns display parameters to each value in a field to generate thematic maps.
• A list of values that are correlated to a range of other values. For example, according to a soil type name, reference to this table can identify the corresponding compressive strength, percolation, and erosion potential rating.
• A file that correlates a user defined ID number permanently assigned to a spatial feature with machine-readable ID number that is subject to occasional change.