Rights in realty which in the legal sense amount to real property (extending in duration one or more lives or in perpetuity) are termed "estates," while those which are personal property are known as chattel interests. There may be both estates and chattel interests in the same piece of realty and several of each. The principal chattel interests are leaseholds (Chap. XI) and liens (Chap. III). The most common estates are, fee simple, fees determinable and conditional, life estates and remainders, dower, curtesy, tenancy in common, joint tenancy and tenancy by the entirety.