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Initially, the term Low Level Format was used to denote a process of placing address marks on the magnetic surface of a rotational hard drive. A disk head used these marks to determine location of sectors. Such an approach was used in the days when disks were supplied separately from the controllers. Each controller marked a disk surface with its own incompatible labels. When moving a disk between different controllers it was needed to reformat the disk, i.e. to write appropriate address marks.

Since circa 1994, disk vendors have been producing disks with built-in controllers where sector address marks are applied directly on the factory. So Low Level Format doesn't apply to the modern hard disks.

Nowadays, the term Low Level Format is preserved and most often used to denote a process of filling a disk with zeroes.

Dnes je to pouhé (definitivní) smazaní dat ... s nějakým "reformátem" to nemá nic společného.