When taking a trip abroad and using your destination country's currency, you will have three choices:
Some drawbacks are that check card ATMs don't always work in each country you visit, especially those that are still developing. One currency exchange location may be much higher than the next or the one in the airport you just left was the best. It is frustrating indeed. Using a credit card may be a good idea due to the rewards points and some even have medical insurance abroad.
Over the years of traveling to South America, I have found that getting my cash using a U.S. debit card from an international bank's ATM that is also based in the U.S. had lower fees (Citi, BofA, HSBC and some local banks) than the travel agencies or cambio (exchange) stores. Some banks even reimbursed the ATM international fees up to $10 a month or all. So, in my case, I would receive the best rates to get the local currency for just $2.50 USD, when the ATM surcharge fee is $12.50.
That is still win-win but risky if you are in the wrong place or unfamiliar with the language. So, as a disclaimer, I would not recommend this route. If you like old school travel, you can always cash the traveler's checks at the foreign bank but they are becoming archaic and not supported widely by all banks.
Also, the worst place to exchange money is at the airport you are departing from prior to reaching your destination country. It has been by far the most unfavorable rate I have experienced.
Here are some common currency symbols you will see in the most visited countries.
€ - Euro
$ - USD, CAD, AUD...
£ - British Sterling Pound
¥ - Japanese Yen
¥ or 元 - Chinese Yuan Renminbi
R$ - Brazilian Real
฿ - Thai Baht
R - Indian Rupee