The image store is a collection of image groups that stores the .wim images and helps the client computer obtain and install the images. An image group is a collection of images that share security options and file resources. An image group consists of the following two components:

The storage structure of the image group uses the imaging feature called “capture by reference.” This feature is most commonly used with “split” .wim files, which are the smaller pieces that result when you break up a large .wim file (typically so that you can fit the pieces of the file onto CDs). The image store in Windows Deployment Services takes this concept a step farther by creating a split media set consisting of two parts: one part that contains an “empty” .wim file that contains only the definition of the image, and another part that contains all the file resources for an image. This storage method is more efficient than the Single Instance Store service used in Remote Installation Services (RIS) in Windows Server 2003.