Let us make it simple and a virtual ticket means that you can take a photo of screen on which screenshot comes on E-ticket booking and one need not carry the physical print out.
In case any doubt for veracity for the announcement one can see IRCTC website which states that Commuters can now carry their Electronic Reservation Slip (ERS) virtually. The screen shot has been taken from Indian railway website. What this essentially means is you can just show a screenshot of your e-ticket on any device and it will be treated as Valid. Book your ticket online, take a snapshot using your mobile camera of the e-ticket and show it to Ticket Checker along with your Valid Identity Proof.
Thank God ! Indian railways is waking up to the reality and is now doing the effort to save the cutting of trees as it do not make sense if one can show the e-ticket. Login to https://www.irctc(dot)co(dot)in/. Hope this problem is also resolved in e-ticket booking for airlines also.