In light of budgetary constraints, policy makers require the latest knowledge base of the quality dimensions that are the most important for ensuring children's development and early learning. Current research, however, is often narrow in focus or limited to programme-level or national-level conclusions. To take stock of and to expand the knowledge base on this topic, the OECD has commissioned a cross-national literature review and meta-analysis of the relationship between structure and process quality in early childhood education and care and links of quality to child development and early learning, conducted in 2017. Structural characteristics are conceptualised as more distal indicators of quality that refer to the infrastructure, whereas process quality concerns the more proximal processes of children's everyday experiences. Results are organised into three thematic policy levers that build on the Starting Strong III Quality Toolbox and later the European Union (EU) Proposal for key principles of a Quality Framework for Early Childhood Education and Care. The report then concludes with an overview of key insights and avenues for further research. (author abstract)