The General Agreement on Trade in Services (GATS) is a treaty of the World Trade Organisation (WTO) that entered into force in 1995.
The objectives are
All members of the WTO are parties to the GATS.
The fundamental principles of the GATS apply, in principle, to all service sectors.
There are two exceptions
The GATS also applies to all services procured by all levels of government (central, regional, local, etc.).
Governments remain free to decide which services sectors they actually liberalise.
Most-favoured-nation treatment (MFN) ensures that each signatory country treats services and service suppliers of any member country indiscriminately, no less favourably than those of any another country, under the conditions and limits mentioned in the Schedule of Specific Commitments.
except under certain conditions, two countries cannot make preferential arrangements that are discriminatory to others
The National treatment principle states that each member country treats services of another member country no less favourably than its own national products, under the conditions and limits mentioned in the Schedules of Specific Commitments.
countries cannot operate discriminatory measures benefiting domestic services or service suppliers
The GATS covers all services with few exceptions. The list of services sectors and sub-sectors covered are found in the Services sectoral classification list.