Error mounting /dev/sdc1 at /media/bmike1/3130-3431: Command-line `mount -t "exfat" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,iocharset=utf8,namecase=0,errors=remount-ro,umask=0077" "/dev/sdc1" "/media/bmike1/3130-3431"' exited with non-zero exit status 32: mount: unknown filesystem type 'exfat'

What in the world is 'exfat'? Does anyone know of a way to fix this they could share with me?