The short answer is: Get the type (EAN or UPC) that is dominant in the country that you are selling in. However, if you are selling in many countries you will probably get away with using the same barcode number in every country because most barcode scanners are compatible with both EAN and UPC barcode numbers.
Now for a more detailed answer. Perhaps the words EAN and UPC are just confusing jargon to you right now, but what they mean & the difference between them is easy to explain.
UPC (Universal Product Code) barcodes are used primarily in North America. The UPC is a 12 digit code, unique to a product, which allows it to be scanned and read in virtually any major retail establishment.
The EAN (European Article Number) is an expanded UPC with 13 digits. The first 2 or 3 are the country code (the following 9 or 10 are data digits and the final digit is the checksum). Outside of the USA, the 13-digit EAN is the most common type of barcode found in the world (eg. in the UK, Europe, Asia, the Middle East, Australasia etc).
Both EAN and UPC codes are compatible with most scanning systems, so they can usually be used in any country:
a) EAN-13 codes are compatible with most scanning systems in the USA. This means that imported products labeled with EAN-13 codes do not have to be re-labeled with a different barcode for USA retail sale.
b) UPC codes are compatible with all EAN-13 scanning systems (because the country code for the US is 00 and the missing first digit is assumed to be a zero). Therefore, if you have a UPC barcode on your product, you will be able to use it in any country in the world.
Please click on one of the following links if you need to purchase an EAN or UPC barcode (depending on your location):