Short for I/O Controller Hub, ICH is an
implementation of the Accelerated Hub Architecture (ACHA),
often referred to as the Southbridge, a reference
to the older, three-tier chipset design. It is the slower end of the ACHA, and
most I/O devices are connected to the hub through it.
[Image Source:
INSIDE THE PC, Nigel S. Smith, University of Cambridge Computing Service]