EAN/UPC
These are designed so that they can be read without having to be orientated in front of the scanner. This makes them suitable for retail point of sale applications. Limited to carrying GS1 Global Trade Item Numbers (GTINs) to identify each product line, they are the only type of bar code specified for consumer units but may also be used on cases.

GS1 DataBar
Formerly called RSS, GS1 DataBar is a family of symbols that are smaller than EAN/UPC and can carry additional information such as serial numbers, lot numbers of expiry dates. From 2010 some types of GS1 DataBar will be scanned at the point of sale.

For more information on DataBar click here.

GS1-128
Formerly called EAN-128, GS1-128 bar codes can carry all GS1 identifiers for products, locations, assets and pallets/logistics units and any additional information required.

ITF-14
ITF-14 bar codes can only represent GS1 GTINs, can be printed directly on corrugated cartons, but cannot be used to identify items at retail point of sale.

GS1 Data Matrix
Data Matrix is the only "2D Matrix" symbol specified for use by GS1 and is becoming increasingly the symbol of choice for many in healthcare
Data Matrix requires camera based scanners and so it is not specified for items to be scanned at retail point of sale.