Can someone explain to me easily how a Barcode/UPC works?

Can someone explain to me easily how a Barcode/UPC works?
I am a retailer who has about six different shirts in five sizes that will soon be distributed among numerous stores. I was told I need a Barcode/UPC. Can someone explain that to me in simple terms and give me websites to purchase? Thanks.

Best answer:

You will need a printer and software to create a barcode that can be read by the scanners. Here is a website for a place selling such equipment:

Tags: Barcode/UPC, easily, explain, someone, works.

Under Forum