Cosmic very high-energy gamma rays

The article gives a brief overview, aimed at nonspecialists, about the goals and selected recent results of the detection of very-high energy gamma-rays (energies above 100 GeV) with ground based detectors. The stress is on the physics questions, especially the origin of Galactic Cosmic Rays and the emission of TeV gamma-radiation from active galaxies. Moreover some particle-physics questions which are addressed in this area are discussed.
19 pages, Latex, uses picpro98.sty, 10 eps figures, Invited talk at the XVIII Physics in Collision Conference, June 17-19 1998, to be published in Frascati Physics Series Vol. XI, (pp. 369 - 388)