The Common European Framework of Reference for Languages (CEFR) was developed between 1993 and 1996 by an international working party and published in 2001 by the Council of Europe. It introduced six common reference levels (A1-C2) to standardize descriptions of language ability. The CEFR aims to provide a transparent, coherent and comprehensive framework that can be used flexibly for various purposes including curriculum design, assessment, and comparing language abilities across different countries and educational systems.