The Education Sector is called to implement a significant and broad mandate, covering many challenging issues in education in a diverse and fast-changing world. More than ever, we need to better focus and ensure greater cohesion in implementing this mandate. This document is part of a series of Technical Notes that have been developed by colleagues in the Education Sector in order to facilitate programme delivery in thematic areas related to the work of the Sector. The Technical Notes are meant to serve as a quick reference tool for UNESCO staff, providing a brief overview including basic knowledge, key priorities for UNESCO and future directions as well as practical information on each topic.