GSTR-1 and GSTR-2 are two of the GST return forms that need to be filed online each month by every registered taxpayers in India. The basic difference between GSTR 1 and GSTR 2 is that the former contains the details of the outward supplies (sales) made by a particular taxpayer in a given month, while the later will be used to furnish the details of inward supplies made by that person/business in that month.