"In theory, there is no difference between theory and practice. But, in practice, there is." CA Ritu explained that Custom Duty is a type of an Indirect tax which is imposed on export and import of goods and services. After implementation of GST in India now custom duty is replaced by IGST. With the introduction of GST, there has been a change in the entire tax system and all indirect taxes such as central excise duty, state-level tax, service charges are now combined under a single tax known as IGST. She explained the concept of IGST with practical illustrations.