Plat map is a document showing the divisions of a piece of land, typically in a subdivision.  It gives the legal descriptions of pieces of real property by lot, street, and block number. It shows the land as subdivided into lots showing the location and boundaries of individual parcels with the streets, alleys, easements, and rights of use over the land of another. Usually a plat map is drawn after the property has been described by some other means, such as a government survey. Once a plat map is prepared, property descriptions are defined by referring to the appropriate map.