What Is Formatting?

Formatting may be high, medium, or low level in type.

Mass-storage mediums store data in units called sectors. Sectors are often grouped together into larger units called tracks. Formatting is the process of initializing sectors and tracks for use in storing data.

Types of Storage Medium

Two types of storage medium exist--primary and secondary. Primary storage refers to non-formattable memory such as RAM. Secondary storage refers to formattable mass storage, including hard drives and magnetic tapes.

Data Sectors

Sectors are divided into system and non-system areas. System areas manage the sector and any data it stores. Non-system areas contain the data itself.

Low Level Formatting

Low-level formatting is used by manufacturers to physically define sectors and tracks on a storage medium and is traditionally done only once during its lifetime.

Medium Level Formatting

Also known as "re-initializing" or "zeroing," medium-level formatting initializes both system and non-system areas of sectors. This prepares a storage medium for new data while destroying any previously stored data. It is often confused with low-level formatting.

High Level Formatting

High-level formatting only initializes system areas of sectors. It is used to quickly prepare a storage medium and may test for damaged sectors. Previous data is left intact, but inaccessible without dedicated tools.

References

• Data Recovery: Gromit's Technical Guide to Partitions/Formatting/Data Recovery
• Dew Associates: Hard Drive Sector Structures