QCD Tests in Hadronic Final States
Various QCD studies based on jet observables in hadronic final states in deep-inelastic scattering and hadron-hadron collisions are presented. Measured quantities are event shape variables, jet rates and jet cross sections. QCD analyses have been performed to determine the value of the strong coupling constant $\alpha_s(M_z)$, the gluon density in the proton and to test power corrections.