These are transcripts of notes taken at (some of) the lectures given at the Mittag-Leffler Institute during the first semester of the year 1996/97 on Enumerative geometry and its interaction with theoretical physics. The first part of this collection consists of notes from talks on the basics of quantum cohomology; the second part treats more advanced topics in quantum cohomology; the third part consists of background material and related topics; an appendix gives a description of Kresch's C-program Farsta for quantum cohomology computations. These notes are meant as a series of snapshots of quantum cohomology as seen by the speakers at the time of their lectures. The reader should bear in mind that quantum cohomology is a growing and rapidly changing field. Many of the writeups have been left in the form of the original talks, which were usually more concerned with giving motivations and a point of view, rather than conveying detailed proofs or attempting to survey the considerably extensive literature on the subject.