Side-step
Basically, you are on final approach for, say, LHR 27L and at the request of either the pilot or ATC you side-step to the other runway, ie 27R.
The side-step can avoid unnecessary go-arounds
Worth noting that side-step procedures aren't exclusive to parallel runways, Zurich has (or did when I was last there 8 years ago) have runways 14 and 16 and side-steps were not uncommon there.