Accreditation is accomplished through a peer review process which requires faculty from other institutions, which have already been accredited, to evaluate a school that has not been accredited or is up for renewal. This process can vary, but it typically evaluates the school's goals, objectives, admission requirements, student services and the quality of the teachers and the course being offered. Many countries have governmental agencies that carry out this process. However, in the United States, it is handled by private accrediting agencies.
Verifying that a school is accredited helps you avoid the so-called "diploma mills" that provide degrees without providing the depth of education that comes from an accredited program. Many schools will use words like "pursuing accreditation," "licensed," "authorized" or "approved" to appear legitimate, even though they are not accredited.
The term "accredited" is often thrown around loosely by schools. It is important to verify that a school is accredited before starting classes. You can do this first by comparing the accrediting agency with list recognized by the U.S Department of Education. You can also refer to the Council for Higher Education Accreditation for similar information regarding the accrediting agency. Groups like the Accrediting Bureau of Health Education Schools and the Accrediting Commission of Career Schools and Colleges, which are both recognized by the U.S Department of Education, are examples of recognized accrediting agencies.
There are many schools that offer distance learning and have been accredited. These include Capella University, which focuses on programs for working adults, Walden University, which has over 40 degree programs to choose from and Kaplan University, which offers a wide variety of undergraduate, post graduate and continuing education courses.