Eli5 what it means when a currency is said to be backed by gold

Question

I see this all the time, mostly when references are made about the dollar and how it was once backed by gold

In: 164

Answer 1

It means at any time you can go to the body that issues the currency and exchange it for a specific weight in gold. Gold prices fluctuate relative to the dollar now, so the amount of gold you can get from a dollar is not guaranteed, so the dollar is not backed by gold.