Difference of nil rated and exempted rated

Based on the Economic criteria goods are mainly classified as Nil rate goods or exempted goods however both are of - 0- value

NIL rated goods will be slowly or drastically changed as per economic scenario to increase rates .

But Exempted goods rates cannot be brought under taxable rates since it is for social requirement of the society or weaker section or policy of importance

for example - cancer / TB eradication programme ( in medical ) infrastructure development for common usage /

such exemption will be for a long period based on international commitment or scenario