Erasing Method Question

Forgive the perhaps ignorant question, but could someone tell me what the difference is between these two wiping schemes. I guess I just want to know what is being done here and which one is "better", or more secure. Why would someone use one over the other?

 

Its just describing what will be written to disk.

I suggest two random data passes and that should be sufficient for security.

If you really have something sensitive (I mean like top secret nsa stuff) add another pass or two if you want to feel paranoid.

don't do any pattern writes. (all 0's, or 10101010, or 12341234 etc.)