To clarify, they are not one and the same: VVL (variable valve lift) allows you to set two different cam profiles (one for low RPM and one for high RPM, with the former setting being the lower of the two), while VVT (variable valve timing) constantly adjusts the valve opening and closing intervals for improved power and efficiency. In 2018, VVT is virtually a must-have (even OHV engines can have it) given its benefits, although VVL (on 2v and 4v SOHC/DOHC engines) is optional.