C.E.U stands for Continuing Education Unit. The CEU is a credit unit equal to 10 hours of participation in an accredited program designed for professionals with certificates or licenses to practice various professions.
Doctors, nurses, lawyers, engineers, CPAs, real estate agents, financial advisers and other such professionals are required to participate in continuing education programs for a certain number of hours each year to maintain their certificates or licenses. The annual CEU number required varies by country and occupation.

Who sets the standards?

Sara Meier, Executive Director of IACET (International Association for Continuing Education & Training), explains the history of the CEU: "IACET was developed by a national working group on [continuing education and training] commissioned by the Ministry of Education in 1968. The task force developed the CEU and set universal guidelines for continuing education and training. In 2006, IACET became the ANSI Standard Developing Organization (SDO) and in 2007 the IACET criteria and guidelines for the CEU became the ANSI / IACET Standard. "