A more thorough explanation:

An affirmative defense is a type of defense that a defendant can use in a criminal or civil case. It involves introducing evidence that, if believed, would show that the defendant is not liable for the alleged acts, even if those acts did occur. The burden of proof is on the party raising the affirmative defense to prove that it applies.

Examples of affirmative defenses include:

• Self-defense: This defense is used when a defendant claims that they acted in self-defense to protect themselves from harm.
• Entrapment: This defense is used when a defendant claims that they were induced or coerced by law enforcement to commit a crime that they would not have committed otherwise.
• Insanity: This defense is used when a defendant claims that they were not mentally capable of understanding the nature of their actions or that their mental state prevented them from knowing that their actions were wrong.
• Necessity: This defense is used when a defendant claims that they had to commit the alleged acts in order to prevent a greater harm from occurring.
• Respondeat superior: This defense is used in civil cases when an employer is held liable for the actions of their employee.

It's important to note that raising an affirmative defense does not prevent a party from also raising other defenses. For example, a defendant could raise both self-defense and alibi as defenses in a criminal case.

Some jurisdictions may classify certain defenses as affirmative defenses while others do not. For example, self-defense is considered an affirmative defense in Florida but not in Ohio.

Overall, an affirmative defense is a way for a defendant to argue that they should not be held liable for the alleged acts, even if those acts did occur.