Unless you never want to use the hard drive, memory card, flash drive, or whatnot again, the first method - wiping or scrubbing the data - is what you'll want to do.
Ọ gwụla ma ị chọghị iji draịvụ ike, kaadị ebe nchekwa, ụgbọala mgbagwoju anya, ma ọ bụ ihe ọzọ, ụzọ mbụ - ihichapụ ma ọ bụ kpochapụ data - bụ ihe ịchọrọ ime.