I'm hoping someone will help me understand the differences between DISTINCT
and DISTINCTROW in a SQL query.

Does DISTINCT only return the First of a set of completely redundant values
from among the selected values?

Does DISTINCTROW not return any redundant sets of values from the selected
ones, even if the redundancies occur outside the selected fields?

I'd sure be glad if someone would help shed light on this.  I'm reading
about SQL and the explanation of this is pretty ill-written.