An affidavit is a written declaration under oath, made without notice to the adverse party. A deposition is a written declaration under oath, made upon notice to the adverse party. Oral testimony is that delivered from the lips of the witness.
Affidavit, deposition, oral testimony defined
Ohio Rev. Code Ann. § 2319.02, under Chapter 2319 | Affidavits; Depositions.
Ohio Rev. Code Ann. § 2319.02