A collapses that entire family into one small file . It works by defining "axes" of variation — typically Weight, Width, and Italic (or Slant). You then place a marker anywhere along those axes. Instead of choosing "Bold," you choose "Weight 657." Instead of "Condensed," you choose "Width 85."
Traditionally, a font family is a collection of separate files: Minion Regular, Minion Bold, Minion Italic, Minion Bold Italic, and perhaps Light, Semibold, Black, etc. Each weight or width is its own static file. minion variable concept font
But in 2020, Minion did something unexpected for a 30-year-old typeface. It evolved. A collapses that entire family into one small file