bar code       
noun [ C ] uk/ˈbɑː ˌkəʊd/ us/ˈbɑːr ˌkoʊd/
 条形码
a small rectangular pattern of thick and thin black lines printed on a product, or on its container, so that the details of the product can be read by and recorded on a computer system
  A handheld scanner is used to read bar codes. 用手持式扫描仪读取条形码。 
 Compare: QR code