reynolds number

It's been puzzling me for a long while and there it is again popping up
in the "WIG airfoils" thread: what is this sacred Reynolds number?
I tried our alther friend en.wikipedia but its theory was quite beyond
my level of education* and its examples of oil in a pipe were not really
illuminating - not to mention the spermatozoa and the Major League Baseball.

Is it a property of the wing, or of the whole plane, or do the fuselage
and wing and empennage &C each have their own Reynolds number?
I seem to understand this figure is a measure of aerodymanic quality?
Given a plane's weight and engine power, will it be faster (or slower)
for a higher Reynolds number?

Excuse my stupidity,
KA


*I am only a modest Solaris sysadmin, never went to university...