StackPacks contain configuration information for StackState that is installed when the StackPack (instance) is installed. StackPacks can contain component templates, functions, component actions and views amongst other things. When a StackPack is upgraded to a newer version, the configuration items installed by the previous version of the StackPack will be overwritten by those from the newer StackPack. This means that any manual change made to these configuration items will be overwritten when the StackPack is upgraded.