[Internet] A special file (layer_name.lpk) that contains a layer, a copy of the data, and an XML file that has a brief description of the layer. It can be opened in ArcGIS Desktop (9.3.1 or later) and ArcGIS Explorer 900 using an automatic unpacking process called a “file handler”. Layer packages are created in ArcMap (9.3.1 or later) or ArcGlobe (9.3.1 or later).