What is the purpose of exam?

I have spend my 17 years to sit for exams since I'm born in this world! Did anyone question about it's purpose for existing? It is merely to test the understanding of student or just want to rank and categories them from the best to the worst. Many of us busy preparing for a bunch of exams in every year until no one really try to find out the essence of it! We are just like a slaver of the exam questions. Don't you agree? After our teacher teach us all the knowledge , they will tell us, "all of this is for exam purposes and it is not applicable in our real life!"

I heard this since I attend my primary school. Since everyone know it is not applicable, then why we still need to study for all of this? We all are lost! At least we are conceptually wrong. That's why so many students commit suicide just because a piece of paper! Then what is the problem? Actually we only need to tune our mindsets. We should be taught to apply our knowledge! Try to make our study life more interesting. What we need is creative in our study life!