hells the expansion of a wild card pattern into a list of filenames (called "globbing") is done by the s... and is executed. Thus the command normally sees a list of filenames (like "foo.txt bar.txt etc.txt") whe... arameter expansion" features is to iterate over a list of components in a single variable.
For example,... ther case might be where you'd want to traverse a list of directories that were all part of a path. Here