If you’ve tried copying a file larger that 4GB to a thumb drive you might have received an error saying it’s full, when you know it’s not. This is because of a fie size limit on PC formatted thumbdrives. Here is how to format a thumb drive in Apple format which will allow you to save larger files.
USB drives by default come formatted as something called MS-DOS 32 which is Windows compatible. Unfortunately, it has a maximum limit on the size of any single file to be 4GB. So if you want to copy a very large file you can’t. (Eg OS-X Yosemite installer or large movie files).
Apple formatted thumb drives can handle large files.
Apple formatted drives are also faster. :-)
NOTE: If you format a USB drive in Apple format it cannot be read by a Windows computer. But Apple computers can read a Windows USB drive.