Packaging an application means collecting all of the required files and registry keys in one easy-to-deploy container. Different packaging formats have different containers. The most common method, MSI, has been around for ages. When you deploy a legacy MSI package, the application's files will be copied onto the local hard disk. Components such as DLLs will be registered, and the registry will be modified. Most modern applications are already packaged on delivery. MSI is very common but different formats exist that use .exe files as their container. Most enterprises repackage their applications. In this way settings can be customized and features can be turned on or off. Even though there are software vendors that use application virtualization, a clear majority of them use legacy, natively installed packaging formats as their installers.
Application virtualization captures all changes made by a legacy installer. When you execute the virtualized package, the application thinks...