A: Operating System Installers are the complete OS installation media imported into the configuration manager server. Operating System Installers are used to create custom images through the System Center Configuration Manager (SCCM) 2012 Build and Capture task sequences.
Operation System Images are the actual Windows Imaging Format (WIM) files that contain OS images.
These WIM files might come directly from the Windows installation media, from a custom process and captured using ImageX, or created through the SCCM 2012 Build and Capture process as discussed in the previous paragraph. Typically, you’d use Operating System Images when deploying OSs via task sequences.