Cal. Code of Civil Procedure § 2025.280

(a) The service of a deposition notice under Section 2025.240 is effective to require any deponent who is a party to the action or an officer, director, managing agent, or employee of a party to attend and to testify, as well as to produce any document, electronically stored information, or tangible thing for inspection and copying. (b) The attendance and testimony of any other deponent, as well as the production by the deponent of any document, electronically stored information, or tangible thing for inspection and copying, requires the service on the deponent of a deposition subpoena under Chapter 6 (commencing with Section 2020.010). (c) A deponent required by notice or subpoena to produce electronically stored information shall provide a means of gaining direct access to, or a translation into a reasonably usable form of, any electronically stored information that is password protected or otherwise inaccessible.