(Compress executables (or any other file type) without affecting their direct functionality, so you don't have to unpack them before run
Compact applications by packing the applications along with their dlls and other resource files
Bind dlls and other resource files to your executable so you can distribute your application as a single (smaller, protected) executable.
Protect your application against reverse-engineering and other hacks.
Password protect your executables or any other file
Password protect your images, pictures, documents, projects, music...etc. and at the same time compress them
Compress and you picture gallery or your music gallery and transform it into a single executable file so you can carry it with you everywhere)