Jet-Studies and $\alpha_s$-determinations at HERA
  Recent results from the H1 and ZEUS Collaborations on inclusive single and multiple jet production in the neutral current deep inelastic scattering of electrons/positrons on protons and the high energy photoproduction on protons at HERA are reported. The results are compared with NLO QCD calculations and have been used to determine the strong interaction coupling constant $\alpha_s$. 
Gerd W. Buschhorn