Generally speaking, yes, you can use your card anywhere it is accepted, including in foreign countries. You may be charged a currency conversion fee or a foreign transaction fee, which typically ranges from 1 percent to 3 percent (but could be higher), though some banks have dropped these fees entirely.
If you plan to use your card outside the U.S., you should notify your card issuer before you leave home. Otherwise, it might freeze your card when it notices foreign transactions, in an effort to avoid fraudulent activity.
Here’s another tip: Make sure you’ve memorized your PIN as numbers, not just letters, since keypads overseas may not display letters on them. For example, if your PIN is HOLLY527, memorize it as 46559527, too.