Education and credentials

I read the other day that some rural hospitals have an emergency room that has zero "doctors" on duty.  I am interested in education and credentials.  Many people use the word "doctor" to mean "physician".  I am a doctor, in that I hold a doctorate degree, obtained from the Graduate School of the University of Maryland.  But don't expect me to prescribe medicines for your child's sore throat.  An associate degree is often a degree obtained after two years of "higher education".  A bachelor's degree usually means four years of higher education.  A master's degree means 1 or 2 years of graduate education beyond the bachelor level and a doctorate may mean 3 or more years beyond the bachelor level.