What's a 1D or linear barcode? What exactly is a second barcode? A 1D or linear barcode is a mix of vertical bars. For some of them you can encode only numbers for other you can encode letters also. Most of barcode scanners can examine them scanning just a line. https://sap-mobile-warehouse-soft49148.bcbloggers.com/26245427/the-definitive-guide-to-barcode-scanning