[Metadatalibrarians] Coverage--Spatial vs. Subject

[Aimee Algier]

What is the difference between mapping a MARC21 651 to Coverage Spatial and mapping it to the Subject element?
 
Thanks in advance,
 
 
Aimee Algier
Head of Technical Services
Harrington Learning Commons, Sobrato Technology Center and Orradre Library
Santa Clara University
500 El Camino Real
Santa Clara, CA 95053
TEL: 408.554.5556
FAX: 408-551-1805
aalgier at scu.edu