Why now I can't just "Empty Trash",
it is "Secure Empty Trash", what is the difference? To me the word "Secure" means keeping.
Macbook Pro 2.4 Ghz/, Mac OS X (10.5.8), Mac Mini 1.25 GHz G4 - OS OS 9.2.2
Secure empty means securing against data recovery. It writes zeros over the location of the deleted file so it can't be recovered by the likes of Data Rescue.
Unless you have sensitive financial stuff or other data that needs completely obliterating, it's unnecessary to use it.