What are the implications of a plea bargain between a defendant and a prosecutor?

" 'While no bargain or agreement can divest the court of the sentencing discretion it inherently possesses [citation], a judge who has accepted a plea bargain is bound to impose a sentence within the limits of that bargain. [Citation.] "A plea agreement is, in essence, a contract between the defendant and the prosecutor to which the court consents to be bound." [Citation.] Should the court consider the plea bargain to be unacceptable, its remedy is to reject it, not to violate it, directly or indirectly. [Citation.] Once the court has accepted the terms of the negotiated plea, "[it] lacks jurisdiction to alter the terms of a plea bargain . . . unless, of course, the parties agree." [Citation.]' [Citation.]" (People v. Tang (1997) 54 Cal.App.4th 669, 680.)