About Barcode Fonts A barcode is a group of parallel alternate black and white lines that represents a group of numbers or characters. Now it has evolved beyond parallel lines to rectangles, dots, hexagons and other geometric patterns. How Barcode works: a photo-type of sensor scans and reads the bar code and turns it into a signal and the sent to a computer network. In the process of scanning, it will calculate and translates measurements (space between bars) into characters; Standards of Barcode: There are a lot of barcode standards for different uses. For example, In the United States, a bar code symbol called UPC is used in the most retail products and they are all numbers.