Many codes have integrated check digits. These are additional numbers or characters added to codes that a computer uses to verify the number is valid. The intention is to reduce the likelihood of miskeying an item and hitting an alternative live item. More often, a system is devised which a computer can calculate using combination of numbers.
Barcode is a graphic symbol used to convey data. Typically the characters in a barcode symbol consist of bars
/space pattern. Barcode is the method of representing data in a visual, machine-readable form. Initially barcodes represented data by varying the width and spacing of parallel lines.
Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects.
A prefix is an affix which is placed before the stem of a word or a string. A product code may have prefix which indicates its group, country, origins, etc.