1)
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.
2)
Build and Capture: This type of task sequence builds an OS image for you by
performing the following steps:
a) Installs Windows from an OS installer
b) Installs software updates
c) Installs software you want to include in the image
d) Performs any other customizations you want to include in the image
e) Prepares a system to be captured to an image by sysprepping it
f) Captures an image of the system to a WIM file
The same wim file could be used for deploying the OS.
Bare Metal OSD - If you are directly booting into PE from boot media or PXE, then it's essentially a bare metal or new computer scenario because you don't care about what's on the drive -- it could be blank, unformatted, you just format and partition and go. OSD always involves booting into PE. Refresh scenarios don't start in PE because you need to capture user data and the best way to do this is from within the current OS. After the data is captured though, the system reboots into PE to continue the process.
OSD is preferred in most of the scenarios.
3) Boot Media - Bootable media contains only the boot image, optional prestart commands and their required files, and Configuration Manager binaries. You create bootable media by using the Create Task Sequence Media Wizard.
https://technet.microsoft.com/en-us/library/hh499044.aspx#BKMK_PlanBootableMedia
Stand-alone Media - Stand-alone media contains everything that is required to deploy the operating system. This includes the task sequence and any other required content. Because everything that is required to deploy the operating system is stored on the stand-alone media, the disk space required for stand-alone media is significantly larger than the disk space required for other types of media.
https://technet.microsoft.com/en-us/library/hh397285.aspx#BKMK_CreateStandAloneMedia
Prestaged Media - Prestaged media contains the boot image and operating system image that you can use to provision a computer. However prestaged media does not contain the task sequence that is used in the deployment process.
https://technet.microsoft.com/en-us/library/hh499044.aspx#BKMK_PlanPrestagedMedia
