Explanation:

GST (one hundred and twenty-second-122 constitutional amendment) bill has finally, been passed in the Lok sabha and the Rajya sabha.
It heralds the first significant step towards the indirect tax reform in India in the last thirty years
 
What is GST?
It is a tax levied when a consumer buys a good or service. It is meant to be a single, comprehensive tax that will subsume all the other smaller indirect taxes on consumption like service tax, etc.
It is a single tax on the supply of goods and services, right from the manufacturer to the end consumer
This is how it is done in most developed countries. More than 160 countries have implemented this system of taxation.
GST does not tax or get into specific commodities.