Definition - What does Affidavit mean?
An affidavit is a sworn statement of fact made by a person as it relates to a situation or action that is being reviewed in a court of law. When an attorney collects proofs on their case, they will ask for statements from people who had direct dealings in the subject matter. The statements have to be sworn by a notary public or commissioner of oaths. After it is sworn, it becomes an affidavit.
Justipedia explains Affidavit
Affidavits must be sworn to be used in court. They are used in most court cases. You will often see an affidavit attached to the complaint, petition, and answer. There are times when the case in court needs further evidence from people relating to the matter. The affidavit is used ongoing within the trial to submit written evidence.