Maybe this will help explain as well.
I'll add a little more to this:
Ignore areas will not calculate end areas for the stations you call out. It will however compute a volume between the station before and after the called out stations. For example, if I have called out ignore areas sta 10+00 to 12+00, and have sections at 9+00 and 13+00 in the file, it will compute the end areas volumes between 9+00 and 13+00
The difference with skip areas is that it will not compute the volume.
The end area for 10+00 and 12+00 would be zero. End area volumes would be between 9+00 (some value) and 10+00 ( 0 ) and then a separate volume between 12+00 (0) and 13+00 (some number)
Skip areas are great for bridge areas that a volume would not be true, ignore areas is better for places that have odd sections that will take away from the validity of the results.
Sera