  An introduction to the theory of the renormalization group in the context of
quantum field theories of relevance to particle physics is presented in the
form of 6 lectures delivered to the British Universities Summer School in
Theoretical Elementary Particle Physics (BUSSTEPP). Emphasis is placed on
gaining a physical understand of the running of the couplings and the Wilsonian
version of the renormalization group is related to conventional perturbative
calculations with dimensional regularization and minimal subtraction. An
introduction is given to some of the remarkable renormalization group
properties of supersymmetric theories.
