A VFB file is a font file created with FontLab Studio. It stores font data such as shapes of letters, numerals, and symbols, in a digital format. The glyphs of these digital fonts make up the alphabet and other symbols. VFB file format stores font in a vector file format. This makes the glyphs independent of scaling without losing quality.
You can open VFB file using FontLab Studio and FontLab TransType Pro.
VFB File Format - More Information
VFB file format is proprietary, and can only be read and written by software that specifically supports it, such as some font-editing software. VFB files are typically used by typographers and graphic designers to create and modify their own custom fonts.