USCBC:The United States Green Building council though it may sound like it is a government entity, it is not. It is actually a non-profit organization. There is no governmental regulations that control their decision making or any part of the organization.
LEED:Leed stands for Leadership in Energy Efficiency and Design. This branch of the USGBC is consensus based. They have stakeholders that take part in Leed. Those stakeholders are mainly architects and builders.
Accreditation: This is given to the person who becomes a LEED expert. It is not given to the buildings.
Certification: This is the title that is given to the buildings after they have gone through all the various process of LEED.