International law, in the everyday legal sense, covers the legal issues that arise when activity crosses national borders. It includes the rules and agreements that govern relations between countries, as well as the practical body of law often called private international law, which addresses cross-border dealings among businesses and individuals.
This field spans many subjects. It can involve treaties and agreements between nations; international trade and the movement of goods and services; cross-border contracts and transactions; disputes that span multiple countries; the recognition and enforcement of foreign judgments and arbitration awards; and questions about which country's courts and laws apply to a given matter. International commercial arbitration — a private process for resolving cross-border disputes — is a significant part of practical international law.
A defining feature is the involvement of more than one legal system. When parties, assets, or events are spread across countries, fundamental questions arise about where a dispute can be heard, which law governs, and how a decision can be enforced abroad. Different countries' laws and procedures may conflict.
For a non-lawyer, the key idea is that crossing borders adds layers of legal complexity that domestic matters do not have. Businesses and individuals commonly consult lawyers with international experience when entering cross-border contracts, expanding into other countries, structuring international transactions, or resolving disputes that involve parties or assets in more than one nation.
