  Application of the background-field method to QCD and the electroweak
Standard Model yields gauge-invariant effective actions giving rise to simple
Ward identities. Within this method, we calculate the quantities that have been
treated in the literature using the pinch technique. Putting the quantum gauge
parameter equal to one, we recover the pinch-technique results as a special
case of the background-field method. The one-particle-irreducible Green
functions of the background-field method fulfil for arbitrary gauge parameters
the desirable theoretical properties that have been noticed within the pinch
technique. Therefore the background-field formalism provides a general
framework for the direct calculation of well-behaved Green functions. Within
this formalism, the pinch technique appears as one of arbitrarily many
equivalent possibilities.
