You might as well face it, the amount of information contained in land records is huge, but it is locked up in arcane and often obsolete legal terminology. Understanding the language unlocks the information in these old records. The modern concept of land ownership or estates have their origins in the 13th Century in England and the methods of land ownership in the United States are derived almost entirely from very early English precedents. The word "estate" itself, dates from feudal times and comes from the Latin word status when a person's ownership of land was connected to his political and personal status in the community.
Genealogical research into land records, especially older records, will quickly illustrate the need for an understanding of both the terms used and the historical context. Land ownership in Anglo-American law is measured in terms of time. The maximum allowable interest in an estate is known as a "fee simple." The term "fee" used in this context means ownership and the additional words added describe the term of ownership. A fee simple is the largest possible estate or ownership in real property. It is sometimes referred to as a fee simple absolute. If the duration of ownership is dependent on any conditions on the grant of title, then the fee is said to be defeasible. There is however, a concept of land ownership more extensive than a fee simple, that is, allodial title where land is owned free and clear of any encumbrances, including liens, mortgages and tax obligations. Allodial title is inalienable, in that it cannot be taken by any operation of law for any reason whatsoever. See Wikipedia.
There is yet another fee interest in land, uncommon today, called fee tail or entail. It describes an estate of inheritance in real property which cannot be sold, devised by will, or otherwise alienated by the owner, but which passes by operation of law to the owner's heirs upon his death. The term fee tail is derived from the Middle Latin foedum talliatum, which means "cut-short fee." See Wikipedia. Fee tail has been abolished in all but four states in the United States: Massachusetts, Maine, Delaware and Rhode Island. However, in the first three states, it can be sold or deeded as any other property would be (the fee tail would only control on death without a will). In Rhode Island, a fee tail is treated as a life estate with remainder in the life tenant's children. New York, for example, abolished it in 1782. Many other states within the U.S. never recognized the fee tail estate at all, as most of the land in the United States of America was deemed allodial. See Wikipedia.
From time to time, I will continue this discussion of the law of real property as it relates to genealogy, because it is always a very good idea to get a basic understanding of the terminology. The use of some of these terms in old wills, deeds and other documents can have tremendous effect on the way the land was transferred and many of the terms, such as the use of a fee tail, can convey very specific ownership interests, which if missed, can make a lot of the subsequent transfers impossible to understand.
Except where noted, see Moynihan, Cornelius J., Introduction to the Law of Real Property: An Historical Background of the Common Law of Real Property and Its Modern Application. St. Paul, MN: West Group, 1962.