[en] This paper reviews the quantum flavour dynamic and fragmentation properties of the heavy leptons and quarks and for the purpose of this report, the heavy flavours are taken to be the τ lepton and the c and b quarks. The production of τ⁺τ^- and the electroweak properties of the τ are first discussed and then the τ charged current decay properties are considered and compared with those of the μ. The role of τ decays in the understanding of Quantum Chromo Dynamics is also considered. The production of heavy quark pairs is considered in the framework of the standard model and the weak neutral current charges of the quarks are presented from a global analysis of all existing data. The weak decays of c and b are discussed and the measurements of lifetimes and leptonic widths considered as input parameters to the eventual determination of the quark weak mixing matrix elements. Finally the fragmentation of c and b quarks is discussed and the various measurements presented. (author)