An I-Deas package file is a file that has been exported out of the I-Deas TDM with all of the relative parts, assemblies and drawing associated with the file being exported out. The links are all contained within the package file. So for example you export out a drawing. The Part that is associated with that drawing is also exported out. Package files is the best way of transfering I-deas native history supported files between I-Deas users. There is also universal files but they do not have associativity back to the TDM. Now if you are using Teamcenter I do not know how package files interact with this.