There are two main ways barcodes are used. They are either included in artwork that is used to print thousands of items all with the same barcode on them, or they are printed individually.
If you are printing one barcode thousands of times then a barcode program is probably the best way to create the barcode.
With individual barcodes a barcode font is the best way to produce them.
If you are creating a barcode to use within a page layout program, eg Quark® Xpress, or Adobe® In-Design®. The barcode program is the best way of creating a barcode to use within these programs. The barcode can be created as an EPSF or TIFF file. You can also save the barcode in Illustrator® format.
If large numbers of different barcodes need to be produced a barcode font is usually the easiest way to produce the barcodes. Most database programs have label layouts defined within them. The barcode number that the human can read has to be converted into a set of characters that can be displayed as a barcode when the barcode font is used.