  These are the expanded and detailed notes of the lectures given by the
authors during the school and workshop entitled "Liaison and Related Topics,"
held at the Politecnico di Torino during the period October 1-5, 2001. In these
notes we have attempted to cover liaison theory from first principles, through
the main developments (especially in codimension two) and the standard
applications, to the recent developments in Gorenstein liaison and a discussion
of open problems. Given the extensiveness of the subject, it was not possible
to go into great detail in every proof. Still, it is hoped that the material
that we chose will be beneficial and illuminating for the participants, and for
the reader.
