  In this lecture, the physics potential for the e+e- linear collider
experiments ILC and CLIC is reviewed. The experimental conditions are compared
to those at hadron colliders and their intrinsic value for precision
experiments, complementary to the hadron colliders, is discussed. The detector
concepts for ILC and CLIC are outlined in their most important aspects related
to the precision physics. Highlights from the physics program and from the
benchmark studies are given. It is shown that linear colliders are a promising
tool, complementing the LHC in essential ways to test the Standard Model and to
search for new physics.
