Final answer:
Exculpatory evidence is favorable evidence in the government's position that is material to the issue of guilt or punishment and includes evidence that may impact the credibility of a witness.
Step-by-step explanation:
In the context of a criminal trial, the evidence in the government's position that is favorable to the defendant and is material to the issue of guilt or punishment, including evidence that may impact the credibility of a witness, is referred to as exculpatory evidence.