Leadership in Energy and Environmental Design (LEED) is basically a third-party certification program. It is a nationally accepted organization for design, operation and construction of high performance green buildings.

The LEED rating systems address both a wide variety of buildings types, including commercial buildings, homes, neighborhoods, retail, healthcare, and schools, as well as every phase of the building lifecycle including design, construction, operations and maintenance.[3] Projects may earn one of four levels of LEED certification (Certified, Silver, Gold or Platinum) by achieving a given number of point-based credits within the rating system.

There are 4 Levels: Certified, Silver, Gold, Platinum

Link: www.usgbc.org/leed