VLS or Valk Last Slot is a Last Slot Last Layer (LSLL) algorithm set, which both orients the last layer while inserting the last pair.
The algorithm set is named after Mats Valk, who along with Rowe Hessler published and popularized the algorithem set.
VLS is a superset of Winter Variation, named after Lucas Winter who published a set that solves OLL with a solved connected pair (F2L 1).
Mats used VLS to break the (former) world record of 4.74sec