The gold standard is a monetary system where currencies are backed by a fixed quantity of gold, facilitating international payments and fixed exchange rates. Initially adopted in Great Britain in 1821, it allowed for significant trade stability but faced challenges, such as lack of flexibility and economic crises, leading to its abandonment during World War I and the Great Depression. Despite efforts to revive it post-war, the gold standard ultimately collapsed by 1937 due to violations and economic pressures.