From the Document: "The annual National Defense Authorization Act (NDAA) has a legacy of regular passage. FY2020 marked the 59th consecutive year for which an annual defense authorization was enacted. Many defense policymakers and officials see the bill as a reliable legislative vehicle for a range of policy matters. In recent years, the NDAA has included several hundred pages of policy provisions and annual authorizations of appropriations in excess of $700 billion. Unlike an appropriations bill, the NDAA does not provide budget authority for the Department of Defense (DOD). Instead, the NDAA establishes or continues defense programs, policies, projects, or activities at DOD and other federal agencies, and provides guidance on how the appropriated funds are to be used in carrying out those authorized activities. This primer provides an overview of the structure and organization of the NDAA."
CRS In Focus, IF10516
Congressional Research Service: https://crsreports.congress.gov/