Decree” means the formal expression of an adjudication which, so far as regards the Court expressing it, conclusively determines the rights of the parties with regard to all or any of the matters in controversy in the suit and may be either preliminary or final. It shall be deemed to include the rejection of a plaint and the determination of any question within section 144, but shall not include–
(a) any adjudication from which an appeal lies an appeal from an order, or
(b) any order of dismissal for default.
Explanation: A decree is preliminary when further proceedings have to be taken before the suit can be completely disposed of. It is final when such adjudication completely disposes of the suit. It may be partly preliminary and partly final;