Accreditation is a process used in the US to assure the quality of the education that students receive. It is a voluntary, nongovernmental, peer-review process that occurs on a regular basis.
There are two types of accreditation: institutional and specialized/programmatic:
Accreditation is NOT a ranking system. It is a system that assures the educational institution or program meets a defined set of quality standards, but it does not compare institutions and programs against others.
Accreditation is NOT granted to individuals. Individuals may be certified, licensed or registered, but they are not accredited.
Additional information about the value of accreditation is provided by the Council for Higher Education.