§ 422 Affidavit defined.

Here's a plain English summary of this rule:

An affidavit is simply a written statement that someone signs under oath. This means the person is legally promising that what they wrote is true, and they can face legal trouble if they lie in it.

The key thing about an affidavit is that it's made without telling the other side in the case beforehand. The person writing it doesn't need to give notice to the opposing party before signing it. This is different from testimony given in court, where both sides are present and can respond in real time.

Affidavits are often used to present facts or evidence in a case without requiring someone to show up in person. Courts accept them as a way to get sworn information on the record, but because the other party wasn't there when it was made, there are usually other rules about how and when affidavits can be used as evidence.