What are the beliefs behind Wai Kru Ceremony?

I think that theres only wai kru day onlybecause its for the students to ask their teachers their blessing and gratitude for their studies. but that’s a good thing, nower days students buy their teachers roses or a pan full of flowers to their teachers to show them how much respect you have for them or love them. Some kids say that their teachers are like their second parents, or mom and dad 2.0 .