If you say Y here, your kernel will be able to manage low cost mass
storage units such as ATA/(E)IDE and ATAPI units. The most common
cases are IDE hard drives and ATAPI CD-ROM drives.

If your system is pure SCSI and doesn't use these interfaces, you
can say N here.

Integrated Disk Electronics (IDE aka ATA-1) is a connecting standard
for mass storage units such as hard disks. It was designed by
Western Digital and Compaq Computer in 1984. It was then named
ST506. Quite a number of disks use the IDE interface.

AT Attachment (ATA) is the superset of the IDE specifications.
ST506 was also called ATA-1.

Fast-IDE is ATA-2 (also named Fast ATA), Enhanced IDE (EIDE) is
ATA-3. It provides support for larger disks (up to 8.4GB by means of
the LBA standard), more disks (4 instead of 2) and for other mass
storage units such as tapes and cdrom. UDMA/33 (aka UltraDMA/33) is
ATA-4 and provides faster (and more CPU friendly) transfer modes
than previous PIO (Programmed processor Input/Output) from previous
ATA/IDE standards by means of fast DMA controllers.

ATA Packet Interface (ATAPI) is a protocol used by EIDE tape and
CD-ROM drives, similar in many respects to the SCSI protocol.

SMART IDE (Self Monitoring, Analysis and Reporting Technology) was
designed in order to prevent data corruption and disk crash by
detecting pre hardware failure conditions (heat, access time, and
the like...). Disks built since June 1995 may follow this standard.
The kernel itself doesn't manage this; however there are quite a
number of user programs such as smart that can query the status of
SMART parameters from disk drives.

To compile this driver as a module, choose M here: the
module will be called ide-core.

For further information, please read Documentation/ide/ide.txt.

If unsure, say Y.

source code:

drivers/ide/