On the concept of local parton-hadron duality

In the last decade jet physics has been intensively studied at both e+e- and hadronic colliders. With the start of LEP activity a wealth of new data has become available. They show that the global features of hadronic jets systems (multiplicities, angular patterns of particle flows, inclusive energy spectra etc), calculated at the parton level, agree very well with the measured ones. This convincingly demonstrates the dominant role of the perturbative phase of jet evolution and strongly supports the hypothesis of local parton-hadron duality. (author)