Characters are encoded by strokes of different thicknesses
With this barcode generator you can generate barcodes based on a variety of different standards. Choose the desired barcode standard, enter the data to be encoded, and start the generation.
Please note: The individual barcode standards support only a limited range of characters, and some require a specific format. Details of the corresponding barcode standard can be found behind the link in the Details field.
DetailsCODABAR at Wikipedia

A barcode is a visual, machine-readable representation of data; the data usually describes something about the object that carries the barcode.