Why are the German people from southern part of Germany called high German?

The term "High German" does not refer to the people from the southern part of Germany. It is a linguistic term used to describe a group of dialects spoken in central and southern Germany, as well as in parts of Austria, Switzerland, Liechtenstein, and Luxembourg. These dialects are characterized by a number of features that distinguish them from the dialects spoken in northern Germany, which are collectively referred to as "Low German".