International
International mostly means something (a company, language, or organization) involving more than a single country. The term international as a word means involvement of, interaction between or encompassing more than one nation, or generally beyond national boundaries. For example, international law, which is applied by more than one country and usually everywhere on Earth, and international language which is a language spoken by residents of more than one country.
International Relations
International Relations (IR) or International Affairs (IA) - commonly also referred to as International Studies (IS) or Global Studies (GS) - is the study of interconnectedness of politics, economics and law on a global level. Depending on the academic institution, it is either a field of political science, an interdisciplinary academic field similar to global studies, or an entirely independent academic discipline in which students take a variety of internationally focused courses in social science and humanities disciplines. In all cases, the field studies relationships between political entities (polities) such as sovereign states, inter-governmental organizations (IGOs), international non-governmental organizations (INGOs), other non-governmental organizations (NGOs), and multinational corporations (MNCs), and the wider world-systems produced by this interaction. International relations is an academic and a public policy field, and so can be positive and normative, because it analyses and formulates the foreign policy of a given state.
Politics
Who will burden himself with your liturgical parterre when the burning questions [brennende Fragen] of the day invite to very different toils?
Karl Rudolf Hagenbach, Grundlinien der Liturgik und Homiletik (1803). "Burning question" used by Edward Miall, M.P., also by Disraeli in the House of Commons (March, 1873).