Advancement means "rank advancement" in BSA terminology. A Cub Scout achieving the rank of Bear or a Scouts BSA member achieving the rank of First Class would be examples of advancement. 

This is different from "training", which is the terminology used for teaching a specific skill to someone, be a Scout or an Adult Leader. 

Advancement comes in several flavors: 

  • Cub Scout advancement 
  • Scouts BSA advancement
  • Venturing advancement 

Requirements for advancement are set by BSA National and implemented by local units (Packs, Troops, or Crews), Districts, and Councils.