Stands for "VESA Local Bus." (VESA stands for "Video Electronics Standards Association"). The VLB, or VL-bus is a hardware interface on the computer's motherboard that is attached to an expansion slot. By connecting a video expansion card to the VLB, you can add extra graphics capabilities to your computer. The interface supports 32-bit data flow at up to 50 MHz. Though the VLB architecture was popular in the early 1990s, it has since been replaced by the newer and faster, but still three-lettered, ISA, PCI, and AGP slots.