A. ExFAT is the Extended File Allocation Table file system and is part of Windows CE 6.0 and Windows Vista SP1/Windows Server 2008 and beyond (i.e., included in Windows 7). ExFAT is designed to be used when NTFS is not suitable or there's too much overhead (e.g., on removable devices).
ExFAT supports drives much larger than 4GB, the previous limit, and actually supports drives up to 16 exbibytes theoretically (I've not seen thumb drives that large yet). ExFAT is the default file system for removable devices as shown below.
