What is the purpose of keywords?
- A keyword is a word or phrase that signifies the meaning or main ideas
of a data set. They often are used as an index to the contents of a
data set. The standards provide for four types of keywords: theme
(the subject of the data set, such as wetlands, vegetation, etc.),
place (the geographic location of the data set, such as Montgomery
County, Yellowstone National Park), stratum (the vertical location of
the data set, such as seafloor, seabed, troposphere, stratosphere),
and temporal (time references for a data set, such as pre-Columbian,
World War II).