Many countries use Federal rather than Devolved Government. They are either large in area, such as Australia, or contain different cultural identities, such as Switzerland, or both, such as Canada.
The federal system allows sovereignty to be shared between a central government/ federal parliaments and state/provincial/canton governments and parliaments.
A federal government and parliament has power over areas such as foreign affairs and economic policy.
A state/provincial/canton government and parliament deals with policies such as education, agriculture, health and transport for their areas.
The country’s constitution defines the respective powers of the two levels.
The United Kingdom developed a Devolved System.
Some parts of the UK have powers handed down to them from Westminster and Whitehall by an Act of Parliament.
This could be changed by a future Westminster Parliament. Since the original devolution extra powers have been granted.
Westminster can take back powers but though this is likely to be politically difficult.
The devolved governments of Scotland, Wales and Northern Ireland now control a wide range of policy areas and can pass their own legislation in relation to them.
English affairs are still controlled by the British Government and the Westminster Parliament. In recent years there has been a surge in support for English Votes for English Laws and for specific England only policies.