Doubt on e-invoicing

Few days back I found an article on e-invoicing......I read it but could not understand it....then I forwarded the same to my friend hoping that he would help me understand the process involved in e-invoice but in vain....So I went to you tube and browsed topics on e-invoicing . Then I got a video which was to some extent helpful...And according to my understanding the buyer requests purchase of some goods .The seller agrees to it consequently uploads the invoice onto the IRP .The IRP later issues an IRN and a QR code to the buyer.But after that I have a doubt...Could someone please help me understand this better...