A data package is a directory that contains a copy of your published maps and all the data necessary to view the map in ArcReader. This directory can be distributed to anyone with ArcReader. This is particularly useful for distributing maps to those who do not normally have access to the data.
The data packaging functionality in Publisher does have some limitations. For some, the limitations will not be a problem; for others, the Data Packager, while not a complete solution, will assist in creating an easily distributable package of maps and data. The topics Troubleshooting data packaging error messages and Troubleshooting data packaging limitations can assist in assessing whether the data packaging limitations will affect the maps and data you want to distribute.
Data packages can be created from published maps in ArcMap or ArcCatalog. In ArcMap, click the Data Packaging button 
to open a file browser that allows you to select one or more published map files (PMF) for packaging. In ArcCatalog, select one or more published maps, right-click, then click Create Data Package.