Structure of MSI package
Logical structure of packages A package describes the installation of one or more full products (Windows Installer does not handle dependencies between products) and is universally identified by a GUID (the PackageCode property). A product is made up of components, grouped into features. Products A single, installed, working program (or set of programs) is a product. A product is identified by a unique GUID (the ProductCode property) provides an authoritative identity throughout the world. The GUID, in combination with the version number (ProductVersion property) allow for release management of the software's files and registry keys. A product is not the same as a package: a package is identified by a unique GUID (stored in the Summary Information Stream) and provides identity and release management for all the contents of the .MSI file. Release management of a Product pertains only to changes in the files and registry keys that make up a software application. Release managem...