HI, GPA means Grade Point Average. The GPA is a system of judging a student's performance and is followed throughout the United States. If a student seeking admission to graduate studies has grades in a different system he/she should clearly mention that GPA system does not exist and provide details on the system.

You can check rest information about GPA here: http://www.studyabroad.careers360.com/what-gpa

Hope this helps.

Good Luck.