ATA and IDE

The original ATA was the primary technology for connecting IDE (Integrated Drive Electronics) hard disk drives to PCs for data storage. ATA would often refer to the technology of the controller (a circuit board or chip), while IDE would refer to the drive type, connector and ribbon cable.

Other ATA Standards

Later, ATA-2 controllers connected to EIDE (Enhanced IDE) disks, which were faster. The ATAPI (ATA Packet Interface) standard was developed for removable media such as CD-ROM and DVD drives. In years that followed, ATA-3 through ATA-6 standards allowed for "Ultra IDE" disk drives that offered increased data transfer speeds.

ATA vs. SCSI

In their first decade, Macs used SCSI (Small Computer System Interface) for hard drives and other peripherals, as SCSI had a "smart" controller that was fast, reliable and could manage multiple devices, including external devices. (SCSI was also popular with PCs in graphic design or specialized industry.) The extra cost of SCSI devices, however, eventually led Apple to move to ATA/IDE technologies in the late 1990s.

ATA Backward Compatible

IDE and Ultra ATA drives are generally backward compatible with older ATA interfaces (such than an ATA-133 drive will work with an ATA-66 interface). However, newer ATA/IDE drives will operate at the older interface's speeds. (The reverse is also true: older drives can be used, in most cases, with newer controllers.)

SATA and PATA

In the late 2000s, PCs and Macs turned increasingly to SATA ("serial ATA") technology for connecting to hard disks and removable drives. SATA supports longer cables, faster speeds and "hot-swapping" of drives (ideal for servers and graphics workstations). To differentiate, legacy ATA technologies are now called PATA ("parallel ATA"). SATA is not backward compatible with PATA.

Source:

EveryMac