"Now a days, any book or item have their own bar code number
Yes, but any barcode number is nothing more than a string of characters which are numerical characters.
Also Note - not all barcodes are numbers ONLY, some are also alpha characters also depending on the barcode symbology used.
how we use that number in our application for that item?"
As Olaf says above, how you use the number is up to you.
* Are you just using the barcode to track documents?
* Are you using the barcode to handle inventory control?
* Are you printing barcoded shipping labels for your product?
* Are you using the barcode labels in a tightly 'controlled' environment such as the medical industry?
* Are you using the barcode to tag new products that you make and intend to sell to others?
* Other uses of barcodes in your application?
If you are receiving barcoded products from a vendor, they are supposed to provide you with a 'catalog' of their products and their associated barcodes values. You can then use the data from that catalog to cross-reference your items as received as part of inventory control.
If you are generating barcodes yourself for
in-house use, you can do things pretty much any way you want. You can choose your own barcode symbology ( see
and you can choose what you want to print and how to use them.
If you are generating barcodes for use
out-of-house such as selling products to another company then you need to follow the established barcode standards for the industry in both the barcode symbology you use and what you print in that symbology.
In some these later cases you might need to register with one of the national or international organizations to get a manufacturer's code which will be used as part of the printed barcode. And you will need to maintain your own barcode 'catalog' which you will have to distribute to your buyers.
I have worked with barcoding in a wide variety of applications for clients since the mid-80's. Once you have clearly defined your needs, then that will guide what you do and how you do it. Sometimes it is VERY simple and other times it can be significantly more complicated.
Good Luck,
JRB-Bldr