This volume contains the writtenversionsof the invitedlecturesand two of the seminars presentedat the "35. InternationaleUniversit~tswochen ffir
Kern- und Teilchenphysik" in Schladming, Austria,which took place from March 2nd to 9th,1996. The titleofthe School was "Perturbativeand
NonperturbativeAspects ofQuantum FieldTheory". The choiceof thistopicwas motivated by the factthatthe presently mostsuccessfultheoryofelementary particlesand theirinteractions,the so-called"Standard Model", turnsout to be stilltoo complicatedto be solvedexplicitlyinmost ofits applications.The lecturesgiven at the school addressthreeofthe main techniquesforrelating the Standard Model, or more generallyquantum fieldtheories,to experimentallymeasurable quantities.These are computer simulationson space-time lattices,perturbativemethods, and thereductionto a simplereffectivetheory by freezingout superficiousdegrees of freedom.