  The International Linear Collider (ILC) is the next large scale project in
accelerator particle physics. Colliding electrons with positrons at energies
from 0.3 TeV up to about 1 TeV, the ILC is expected to provide the accuracy
needed to complement the LHC data and extend the sensitivity to new phenomena
at the high energy frontier and answer some of the fundamental questions in
particle physics and in its relation to Cosmology. This paper reviews some
highlights of the ILC physics program and some of the major challenges for the
accelerator and detector design.
