1. A computer-readable storage medium tangibly embodying an information model for managing party and property information from multiple data sources in a single data structure, the information model comprising: a plurality of legal party objects including first and second legal party objects to represent first and second legal entities, respectively, the first and second legal entities being at least one of an individual, an organization and a public agency; a plurality of revenue-object objects to represent a plurality of taxable items, wherein the first and second legal entities have a tax responsibility with respect to at least one of the plurality of taxable items represented by at least one of the plurality of revenue-object objects; a plurality of legal party role objects including first and second legal party role objects to designate entity role types and to connect the first and second legal party objects respectively to the at least one of the plurality of revenue-object objects, whereby each of the first and second legal party role objects maintains a relationship between the first and second legal party objects and the at least one of the plurality of revenue-object objects; a parcel object, a situs address role object, and a tax authority group role object associated with one of the plurality of revenue-object objects, wherein the plurality of revenue-object objects is inheritable by the parcel object; a plurality of objects associated with the parcel object, wherein at least one of the plurality of objects associated with the parcel object is a description header object to represent a description of a real estate parcel, the description header object having an associated free form description object and a description detail object, wherein the plurality of objects associated with the parcel object includes a parcel history object and an associated re-description object to represent a prior description of the real estate parcel; a situs address object associated with the situs address role object to represent the physical address of a taxable item; a tax authority group object associated with the tax authority group role object to represent a tax authority that levies a tax against a taxable item; and a tax authority group history object associated with the tax authority group role object to represent a change in at least one tax authority, wherein the tax authority group history object is associated with an annexation object, wherein each of the parcel object, the plurality of objects associated with the parcel object, the situs address object, the tax authority group object and the tax authority group history object are tangibly embodied on the computer readable medium.