What is the Silver Standard?

By GovMint :

The silver standard is a monetary system where the value of a country's currency is directly linked to a specific amount of silver. Historically, this system was widely used, with silver serving as the primary basis for currency at some point in time for many civilizations including ancient Greece, China, and the United States.

The silver standard was prevalent until the late 19th and early 20th centuries, when many countries began transitioning to a gold standard. By 1935, most countries, including China and Hong Kong, had abandoned the silver standard in favor of fiat currencies or the gold standard.

Sources Used:

https://www.investopedia.com/terms/s/silver-standard.asp