Sdfat does not name a type?

second_try:45: error: 'SdFat' does not name a type
SdFat SD;
^
Multiple libraries were found for "SD.h"
Used: /home/pi/Arduino/libraries/SD
Not used: /home/pi/Desktop/arduino-1.8.5/arduino-1.8.5/libraries/SD
exit status 1
'SdFat' does not name a type