Ethnography
Ethnography is a method of studying and learning about a person or group of people. Typically, ethnography involves the study of a small group of subjects in their own environment. Rather than looking at a small set of variables and a large number of subjects ("the big picture"), the ethnographer attempts to get a detailed understanding of the circumstances of the few subjects being studied. Ethnographic accounts, then, are both descriptive and interpretive; descriptive, because detail is so crucial, and interpretive, because the ethnographer must determine the significance of what she observes without gathering broad, statistical information.
from Washington State University learning commons glossary http://www.wsu.edu:8001/vcwsu/commons/topics/culture/glossary/ethnography.html
Ethnology
Ethnology is a genre of anthropological study, involving the systematic comparison of the folklore, beliefs and practices of different societies. Among its goals are the reconstruction of human history, and the formulation of laws of culture and culture change, and the formulation of generalizations about human nature. In some parts of the world (like the USA and Great Brittain) it is allso referred to as cultural anthropology, although it is not entirely the same. Ethnology has been a scientific discipline since the late 18th century but many of the world' s best known minds of all times have been studying various peoples and their traits.
from Wikipedia http://en.wikipedia.org/wiki/Ethnology