The Research Excellence Framework (REF) is an assessment that is carried out periodically to determine the quality of research in UK higher education institutions. The results are used by the higher education funding bodies for England, Scotland, Wales and Northern Ireland to allocate research funding.
Keep an eye on the REF 2029 webpages for continual updates.
The REF 2021 website and REF 2014 webpages are still available for reference.