What is a lpk file and how do I open a lpk file?

These are files known as ArcGIS Layer Packages and data files that users created using ArcGIS Desktop developed by ESRI. ArcGIS Desktop is an application for software package mapping and visualization, useful for the increase and improvement of understanding and decision-making, automation of various cartography aspects, simplifying data design, as well as the creation and sharing of information. The LPK files created using this software contain not only the map layer but also the data of that map layer. This map layer data contained in LPK files can be imported into another map. LPK files are used to share self-contained map layers to others. LPK files can be uploaded and shared over the net using the ArcGIS Online service. Both ArcMap and ArcGlobe use LPK files wherein these programs are both parts of the ArcGIS Desktop software. The ESRI ArcGIS Desktop is used to open LPK files categorized as GIS files.