E-PAN is the PAN provided in PDF format rather than physical card. The E-PAN card in PDF format will be sent to e-mail ID mentioned in PAN application form.
If the physical PAN Card is not required, then PAN applicant will have to indicate at the time of submission of PAN application. In such cases, Email ID will be mandatory & E-PAN Card will be sent to the PAN applicant at the email ID.
Physical PAN Card will not be dispatched in such cases. Charges for E-PAN card is different from physical PAN card.
Source: Income Tax India’s Official Website