California Code, Code of Civil Procedure - CCP § 1014

A defendant appears in an action when the defendant answers, demurs, files a notice of motion to strike, files a notice of motion to transfer pursuant to Section 396b, moves for reclassification pursuant to Section 403.040, gives the plaintiff written notice of appearance, or when an attorney gives notice of appearance for the defendant. After appearance, a defendant or the defendant's attorney is entitled to notice of all subsequent proceedings of which notice is required to be given. Where a defendant has not appeared, service of notice or papers need not be made upon the defendant.