以上术语均与永赁地权益或土地永赁权有关。首先是estate by entirety (也称为 tenancy by the entireties；tenancy by the entirety ；estate by the entireties)和 joint tenancy，前者主要指夫妻之间的对永赁地权益之共有，后者内涵较广，不一定特指夫妻之间的共有关系。其共同点在于两者所指的关系中，如发生一共同共有人死亡的情况，生存者可获得死者的权益。不同之处在于在estate by entirety所确定的关系中，夫妻被视为一人而拥有土地权益，当一方死亡，只有生存的配偶才有享有死者财产权益的权利，即当一方配偶死亡，其名下的财产权益便自动由其配偶受领，而其他人，包括死者的其他继承人均不能享受，故estate by entirety应译为“夫妻共同共有不动产权益”[1];在此点上，其与我国婚姻法中的“夫妻共同财产制”有较大的差异。 此外，estate by entirety在夫妻财产关系中视夫妻为一人而拥有土地，如一方死亡，另一方配偶有权按joint tenancy之关系受领死者的财产，如双方离婚，其则转换为tenancy in common之关系。在joint tenancy所确定的关系中，如一方死亡，其财产可由其他任何数量的生存的共同共有者分享，直至最后一个survivor; 因joint tenancy涉及到两人以上的共同共有所有关系，故译为“共同共有权益”[2]。tenancy in common (也称为 estate in common或common tenancy)则为“按份共有权益”，指两人或多人共有一份土地，如其中一人死亡，其权利应由其继承人享有， 而不是由其他共同所有人享有，在此点上其与joint tenancy有明显差异[3]。
 
[1] "A common-law estate, based on the doctrine that husband and wife are one，and that a conveyance of real property to husband and wife creates but one estate. An estate held by husband and wife together so long as both live，and，after the death of either，by the survivor." Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 380, West Publishing Co. (1991).
[2]“A tenancy in which two or more parties hold equal and simultaneously created interest in the same property and in which title to the entire property is to remain to the survivors upon the death of one of them (as a spouse) and so on to the last survivor. ”Cf. Linda Picard Wood, J. D. Merriam Webster's Dictionary of Law，at p. 491，Merriam-Webster, Incorporated (1996).
[3]“A tenancy by two or more persons, in equal or unequal undivided shares, each person having an equal right to possess the whole property but no right of survivorship. ” Cf. Bryan A. Gamer, Black's Law Dictionary, 7th edition, at p. 1478, West Group (1999).