What it is
App Volumes delivers applications as virtual containers rather than as installations. A package holds one application or several. It is assigned to a person or to a machine, and it is there the moment they sign in, without having been installed into the image.
How it works
The App Volumes Manager is the console and the bookkeeping: it holds the packages and the writable volumes, it talks to vCenter for the virtual machines, and it keeps every assignment in a SQL database.
At logon the packages assigned to that person are attached to their profile and the applications in them are immediately available. If the person has a writable volume, that attaches too, and it is where their own data and settings live. At logoff both detach and nothing of them remains on the machine.
What it is for
Cutting the number of master images. An estate that installs every application into the image ends up with an image per department, and then maintains all of them on patch Tuesday. With App Volumes there is one image and a catalogue of packages, and updating an application means updating a package rather than rebuilding a desktop.
The second use is licensing. An application that only forty people are licensed for is assigned to forty people, instead of sitting installed on nine hundred desktops and being counted there.
What to watch
Not every application packages cleanly. Drivers, kernel-level components and anything that insists on writing to the same path at install time are the usual arguments. Find those before the design, not after the pilot: the ones that resist are also the ones the business cannot do without.