What is e-invoicing and which all businesses are required to generate e-invoicing?

The e-invoicing was introduced on 1st October 2020, for tax payers with an aggregate turnover exceeding Rs. 500 crore. This was also extended on businesses from 1st January 2021 whose aggregate turnover is exceeding Rs. 100 crore.

source https://www.caclubindia.com/articles/what-is-einvoicing-and-which-all-businesses-are-required-to-generate-einvoicing-45909.asp