This 3 sentence summary provides the key details about the Windows 8 USB Installer Maker tool:
The Windows 8 USB Installer Maker tool allows users to create a bootable USB drive containing the Windows 8 ISO file that can then be used to install Windows 8 directly from the USB, by downloading the Windows 8 ISO, running the tool to copy it to a USB drive, and then rebooting the computer to install Windows 8 from the USB drive. The tool formats and prepares the USB drive, copies the ISO files, and makes the USB drive bootable to allow installing Windows 8 using only a USB drive and ISO file.