Great Britain is the official name given to the two kingdoms of England and Scotland, and the principality of Wales. The United Kingdom (UK) includes these areas as well as Northern Ireland. Britain refers to only England and Wales, though some will shorten Great Britain with this term.
The Royal Standard of Scotland, also known as the Banner of the King of Scots, or more commonly the Lion Rampant of Scotland, is the Scottish Royal Banner of Arms. Its correct use is restricted by an Act of the Parliament of Scotland to only a few Great Officers of State who officially represent The Sovereign in Scotland. Scotland has not had its own monarchy since the Act of Union with England in 1707. Queen Elizabeth II is monarch of United Kingdom of Great Britain and Northern Ireland.
Correction, flag of the United Kingdom. The flag of Great Britain doesn't have the St Patrick cross as Ireland was not fully incorporated under the crown until 1807 I.e the formation of the United Kingdom of Great Britain and Ireland. Wales is not featured because it's a principality, not a kingdom.