Everyone knows that the USD is the most popular and useable currency in the world. The EUR/ euro is an all-time rival of the US Dollar. But this has not always been the case, with the dollar-to-euro rate fluctuating over time. 

In general, a country's currency is strong when it has a lot of value. A weak currency has less value and can even become worthless. This happens because the country prints too much of that type of money. For example, there is inflation in Japan and people buy fewer things because they have so much money already.

Euro

Currently 1 EUR or of the US Dollar of 1.13 when I am writing this article. As of November 2021, the euro is worth about 1.13 dollars. If a currency is weak, it can help boost exports from the U.S., but sometimes a strong currency can also be bad because it makes imports more expensive in the U.S. In the European Union, each country is responsible for its own policies. They can't print money or do anything else without asking the other countries in the union. In some countries, they had a hard time doing that and ended up in crisis.

British Pound

1 GBP = $1.34 The Bank of England has done well over time. The GBP is used to be worth more than the USD, but it wasn't always true. This changed in the 1980s, and during this time, the British pound was worth more than the U.S. dollar again until 1997 when things changed again and it became about equal with the American dollar.

Swiss Franc

1 CHF = $1.01 The Swiss franc has always been a strong currency. Currently, CHF is worth more than USD. Switzerland has a lot of money and doesn't easily give it away. In the 1920s, the U.S. dollar was worth more than 4 Swiss francs because of high inflation in Switzerland from WWI.

Omani Rial

1 OMR = $2.60, Oman is a country where the U.S. dollar is worth 1.6 rials (OMR). That is because Oman has protected its own money from war and conflict in the Middle East to make sure the country's inflation stays low and lending practices favor risk-averse companies.

Kuwaiti Dinar

1 KWD = $3.30. Kuwait has a lot of oil and this helps its economy. The Kuwait Investment Authority makes sure that the country stays successful and prosperous.