From Longman Dictionary of Contemporary Englishbar codeˈbar code ●○○ noun [countable] 
BBTTDa group of thin and thick lines printed on products you buy in a shop, that a computer can read. It contains information such as the price.
BBTTDa group of thin and thick lines printed on products you buy in a shop, that a computer can read. It contains information such as the price.Examples from the Corpus
bar code• There is a bar code plus thirteen digit number on the front of this copy of Everyday Electronics.• When a bar code is read, all that is fed into the computer system is the same number.• Next month some practical bar code hardware and software will be described.• To read in such a small bar code successfully requires a very high degree of resolution.• Without this massive data base, all you read in from the bar code is a meaningless number.• The do-it-yourself bar code user therefore has to write his or her own reader software.From Longman Business Dictionarybar codeˈbar code [countable]COMMERCE a series of lines printed on products sold in a shop that can be read by a machine connected to a computer to give the price, keep a record of the sale etcThe scanner at the checkout recognises the bar code and charges the correct amount. —bar coding noun [uncountable]The use of bar coding has meant that restocking is done automatically. → code 