Euro.
More stable than the US dollar.
Both the pound and the euro are.
The Euro is larger than the US dollar 1 EUR = 1.39140 USD
0.732 Euro is equal to 1 dollar so the Euro is worth more than a dollar.
Currently there is Less than 1 Euro in an American dollar because the Euro is more valuble than the Dollar.... 1.00 EURO=1.42810 USD
More stable than the US dollar.
Both the pound and the euro are.
The Euro is larger than the US dollar 1 EUR = 1.39140 USD
The only currency used in Spain is the Euro.
0.732 Euro is equal to 1 dollar so the Euro is worth more than a dollar.
Currently there is Less than 1 Euro in an American dollar because the Euro is more valuble than the Dollar.... 1.00 EURO=1.42810 USD
The euro is a "stronger" currency than the yen by far.
At 11pm on 10th March 2011 according to currency site XE.com 1 Euro is worth 1 US Dollar and 38 cents.
Currently the exchange rate (Dec 2017) is 1 EUR = 1.19986 USDWhich currency is worth more depends on what a Euro can buy compared to the dollar.
There is no "de facto universal currency". Technically the most probably de facto universal currency is the Yuan used by more than 1/4 of the worlds population. The US Dollar is much less.
Depreciation is when one currency becomes weak against another currency. Appreciation is when one currency becomes stronger than other currency. For example, imagine that current exchange rate is USD/EUR=1.42 and after some time it changed to USD/EUR=1.45, in that case US Dollar depreciated against Euro. If it changes to USD/EUR=1.38 in this case US Dollar appreciates against Euro.
The Euro is the official currency of the European Union, but still not every member uses the currency. Some will eventually switch to the euro and others have refused to use it altogether (such as the UK). From the 1st of January 2014, only 18 of the 28 members of the European Union use the Euro.