Contributions you choose to make to your EPF account on top of the statutory share.
VPF goes into the same EPF account and earns the same declared rate. Your employer does not have to match it.
Interest on your own contributions (VPF included) is taxable on the part of a year's contributions above ₹2,50,000, or above ₹5,00,000 where the employer contributes nothing. Your contribution counts towards Section 123 (formerly 80C) under the old regime.
Figures on this page are filled from the same tax and scheme tables the calculators use, for the current financial year. Every term in the glossary.