File Deletion: What's what?

CCleaner for Windows
1

I have used CCleaner for a while and never bothered to touch "Normal File Deletion" or "Secure File Deletion". I'm not sure what is what? Could someone please define what these two mean? Do these functions wipe out the hard drive or do what it actually says, deletes files?

Thanks.

2
Do these functions wipe out the hard drive or do what it actually says, deletes files?

Deletes the files you want deleted.

Normal File Deletion only deletes the files. Secure File Deletion overwrites the files with zeros per the number of passes you select. Simple 1-pass is sufficient.

http://www.piriform....leaner-settings