Question

You want to securely erase data from your hard drive what can you use to do this and what is the process called

Answer 1

You could Factory Reset a computer or you could smash it with  a hammer

Answer 2

Like Kotero said, you can do factory reset or go through and manually click on each file on the hard drive and click delete. If you don't want to use the hard drive ever again, you can smash it, burn it, run 1000 watts of electricity through it, throw it in the ocean, or throw it off a cliff.