In order to fully understand which Mac data recovery software package is best suited for your needs, it is necessary to understand the terminology associated with data storage and recovery. Understanding file system types is necessary to know exactly what data recovery software to use, since it is necessary that your data recovery program support all of the file system types on the disks and devices that you want to recover data from.
Hierarchical File System (HFS)
HFS is a file system type developed by Apple Inc. for use on computers running Mac OS. Two main variants of HFS exist: Mac OS Standard (a.k.a. HFS Standard or HFS ) and Mac OS extended (a.k.a. HFS extended or HFS+ ). If you are running Mac OS X, your bootable drive is almost certainly using HFS+, not standard HFS. HFS+ allows for larger files with longer file names to be stored on the disk. HFS+ is also one of the file system types used for the iPod music player.
New Technology File System (NTFS)
NTFS is a file system type that is commonly used for Microsoft Windows. It is the standard file system for Windows NT, Windows 2000, Windows XP, Windows Vista and Windows 7. It provides numerous improvements over the FAT file system, including better security and better disk utilization. If you are running a Mac that is dual-booting with a recent version of Microsoft Windows, support for NTFS is necessary to recover this data.
File Allocation Table (FAT)
FAT is file system type that has been used since the late 1970s. Microsoft Windows 95 and 98 used a 32-bit version of FAT called FAT32 for disk storage. Newer versions of Windows and certain embedded devices may use the latest version of FAT, called exFAT, for storage. Mac OS X includes support for FAT for other drives and partitions (not the bootable partition), so it possible that an external drive or a partition to store files uses this file system type.
Other File System Types
Linux supports ext* family file system types, including ext2, ext3 and ext 4, XFS, JFS, RieserFS and btrfs. If you have a Linux partition on your Mac, it is most likely that you are running Linux with ext2, ext3 or ext4 file system type. If you are dual-booting with Sun Solaris, you will likely need support for UFS, UFS (journaling), ZFS or QFS file system types.
Redundant Array of Inexpensive Disks (RAID)
RAID refers to a type of data storage where data is stored across multiple hard disks. Various types of RAID exist, including: RAID 0 (striped disks), RAID 1 (disk mirroring), RAID 3 or 4 (striped disks with dedicated parity), RAID 5 (striped disks with dual parity) and others. Disk striping refers to the process of spreading a file across multiple disks. Disk mirroring refers to storing the same data across multiple disks, so that two or more disks include a full copy of the same file. Parity is used to check whether a file has an error through use of a parity bit.
For more help on recovering files, see our in-depth reviews and side-by-side comparisons of the best Mac data recovery software and/or PC data recovery software. At TopTenREVIEWS We Do the Research So You Don't Have To.