Explanation:

These are the four modes of supply under trade in services, as defined under General Agreement on Trade in Services (WTO).

Mode 1: Cross border supply (supply from the territory of a Party into the territory of the other Party). For example an architect can send his architectural plan through electronic means; a teacher can send teaching material to students in any other country; a doctor sitting in Germany can advise his patient in India through electronic means. In all these cases, trade in services takes place and this is equivalent to cross-border movement of goods.

Mode 2: Consumption abroad (consumption in the territory of a Party by the service consumer of the other Party). For example a tourist using hotel or restaurant services abroad; a ship or aircraft undergoing repair or maintenance services abroad.

Mode 3: Commercial presence (by a service supplier of a Party, through commercial presence in the territory of the other Party). In this case, the service supplier establishes a legal presence in the form of a joint venture/ subsidiary/representative/branch office in the host country and starts supplying services. For example a bank opens its branch in another country.

Mode 4: Presence/movement of natural persons (by a service supplier of a Party, through presence of natural persons of a Party in the territory of the other Party). For example Independent service suppliers or ISS (e.g. doctors, engineers, individual consultants, accountants, etc.) who supply services in another country.

However, GATS covers only temporary movement and not citizenship, residence or employment on a permanent basis in the foreign country.