According to a recent Harvard Business Review article by Suntae Kim, Matthew J. Karlesky, Christopher Myers and Todd Schifeling, a certified B-Corp is defined as follows:
"Certified B Corporations are social enterprises verified by B Lab, a nonprofit organization. B Lab certifies companies based on how they create value for non-shareholding stakeholders, such as their employees, the local community, and the environment. Once a firm crosses a certain performance threshold on these dimensions, it makes amendments to its corporate charter to incorporate the interests of all stakeholders into the fiduciary duties of directors and officers. These steps demonstrate that a firm is following a fundamentally different governance philosophy than a traditional shareholder-centered corporation."
Read the full article on Harvard Business Review here.