  Cosmic infrared background (CIB) contains information about galaxy
luminosities over the entire history of the Universe and can be a powerful
diagnostic of the early populations otherwise inaccessible to telescopic
studies. Its measurements are very difficult because of the strong IR
foregrounds from the Solar system and the Galaxy. Nevertheless, substantial
recent progress in measuring the CIB and its structure has been made. The
measurements now allow to set significant constraints on early galaxy evolution
and, perhaps, even detect the elusive Population III era. We discuss briefly
the theory behind the CIB, review the latest measurements of the CIB and its
structure, and discuss their implications for detecting and/or constraining the
first stars and their epochs.
