California Code of Civil Procedure Sections 2002-2005 Article 1. Mode of Taking the Testimony of Witnesses

2002.  The testimony of witnesses is taken in three modes:
   1. By affidavit;
   2. By deposition;
   3. By oral examination.
2003.  An affidavit is a written declaration under oath, made
without notice to the adverse party.
2004.  A deposition is a written declaration, under oath, made upon
notice to the adverse party, for the purpose of enabling him to
attend and cross-examine.  In all actions and proceedings where the
default of the defendant has been duly entered, and in all
proceedings to obtain letters of administration, or for the probate
of wills and the issuance of letters testamentary thereon, where,
after due and legal notice, those entitled to contest the application
have failed to appear, the entry of said defaults, and the failure
of said persons to appear after notice, shall be deemed to be a
waiver of the right to any further notice of any application or
proceeding to take testimony by deposition in such action or
proceeding.
2005.  An oral examination is an examination in presence of the jury
or tribunal which is to decide the fact or act upon it, the
testimony being heard by the jury or tribunal from the lips of the
witness.