The Lunar Vehicle (LV) is a variant of the OV. NASA had originally conceptualized it as basically an OV with landing legs (Image 1).
Image 1: NASA Space Tug in the lunar lander configuration
The lunar lander is the vehicle that will (obviously) transport humans and cargo from lunar orbit down to the lunar surface and back up again to lunar orbit (Image 2).
Image 2: 1970's era LV lunar lander variant on the Moon