Official development assistance (ODA) is defined by OECD-DAC as government aid that promotes and specifically targets the economic development and welfare of developing countries.

The Organization for Economic Co-operation and Development – Development Assistance Committee (OECD-DAC) is defined by OECD as one of the key forums in which the major bilateral donors work together to increase the effectiveness of their common efforts to support sustainable development. It is a forum of many of the largest providers of aid, including 30 members. 

The United Nations Sustainable Development Group (UNSDG) is a high-level forum for joint policy formation and decision-making. It guides, supports, tracks and oversees the coordination of development operations in 162 countries and territories. It represents nearly 40 operational UN entities working on sustainable development.

The Funding Compact sets out ambitious commitments by Member States and the United Nations Sustainable Development Group to ensure predictable and flexible funding for United Nations development activities.

UN operational activities for development (OAD) includes the activities of UNDS entities that promote the sustainable development and welfare of developing countries and countries in transition. Despite the name, UN OAD includes both development-related long-term activities and activities with a humanitarian assistance focus.

The UN development system (UNDS) are those UN entities defined as carrying out ‘normative, specialised and operational activities for development to support countries in their efforts to implement the 2030 Agenda for Sustainable Development’ or, in short, those with a mandate to promote economic and social development. Contributions to the UNDS consist exclusively of core, voluntary core or earmarked funding for development and humanitarian activities, also referred to as operational activities for development (OAD).

The UN system, which includes all revenue and expenditures aggregated from the 43 reporting UN entities. The UN system receives contributions through four financing instruments, broken down into core and voluntary core contributions, earmarked contributions and revenue from other activities. Contributions to peace operations are included in the UN system but not in the UN development system.

The UN Quadrennial Comprehensive Policy Review (QCPR) is the mechanism through which the General Assembly (GA) assesses the effectiveness, efficiency, coherence and impact of UN operational activities for development and establishes system-wide policy orientations for the UN development system.