Linear barcodes are common types of barcodes that are made of up to four components: the quiet zone, start and stop characters, intercharacter gaps, and the interpretation line.
Between these components, scanners are able to decode information stored within the barcode. Linear barcode symbology (the specific barcode “language”) is a single row of bars and spaces that encode various types of data.
The bars are always black and the spaces are always lighter, typically white. The bars and spaces are used to represent letters and/or numerals.