1.Where is the difference between these softwares?
All of them are for deleting data.
2.Which is the best for me?
I want to have a software that can delete everything and make data irrecoverable. I usually do it with CCleaner (using the wipe free space option). But maybe another software for deleting data can be useful for me.
Maybe these softwares have concrete destiny.
4.Which softwares (like these above) can you recommend to me?