A fee simple, also referred to as fee simple absolute, is an estate over which the owner has unlimited power of disposition in perpetuity without any conditions or limitations. A fee simple interest is created with, for example, the following: “to John and his heirs.”
The fee simple absolute is the highest possible estate one can own. The owner of a fee simple absolute and his heirs (as determined by the relevant Intestacy Act), successors (someone who has legally stepped into the shoes of the owner), and assigns (someone who is assigned the right to the property) may remain in possession forever. The estate ends only if the owner dies intestate (without a written will) and with no heirs, in which case the estate escheats (passes by default) to the government. The government may also legally take the property through its right of eminent domain by paying the owner the property’s fair market value.
“Although it is probably good practice to use the word ‘absolute’ whenever one is referring to an estate in fee simple that is free of special limitation, conditional subsequent, or executory limitation, lawyers frequently refer to such an estate as a ‘fee simple’ even as a ‘fee.’”
Source: Thomas F. Bergin & Paul G. Haskell, Preface to Estates in Land and Future Interests 24 (2d ed. 1984)