A company can be any size to use barcodes.
Both terms apply to the same device. There isn't a difference.
IBM. IBM are the creators of the bar code, so I'm sure their the first to ever scan a bar code. The first bar code was on a 10 pack of Wrigley's gum. The first retail store to scan that pack of gum was at a Marsh Supermarket in Troy, Ohio.
Plessey Telecommunications
They are valid as all tickets printed will refer to the same bar code. But if 1 ticket is used to enter a venue, the bar code is scanned so all other copies of the same bar code are now deemed used.
There are several companies that make hand held bar code readers. You can even get an app for your smart phone that will read bar codes. A major manufacturer of bar code reader is Motorola (they bought "Symbol" the leading bar code reader company a while back). Look at: http://www.motorola.com/Business/US-EN/Business+Product+and+Services/Bar+Code+Scanning
"There are a number of places online where you can buy a bar code printer. Zebra makes bar code printers, which you can purchase at their web site. You can also buy them from Brother, which also makes bar code printers. Just go to their company web sites and choose one that most appropriately fits your needs."
the use by date company name and bar code that is all
Yes, and no. A UPC is a Universal Product Code which is a Barcode. There are however Barcodes that do not conform to the Universal Product Code and they are just Barcodes. A company may use barcodes internally to track inventory but that barcode may not be a UPC.
Motorola, which purchased the Symbol company in 2007, produces the products for the company, including bar code scanners. For the manufacturing process, Motorola uses such companies as Pacific Solutions in Bengaluru, India and Quadrant Technology in Kolkata, India
Everything the store sells - is stored on a computer - along with the price. The bar-code on the item is unique - in that (for example) all identically-sized tins of carrots from the same supplier have the same bar-code. When the tin is scanned, the computer interprets the bar-code and adds the item to your bill. It also prints the item price.
A barcode reader (or barcode scanner) is an electronic device for reading printed barcodes.A bar code scanner reads bar codes.Bar codes contain data, typically numeric or alphanumeric data. While bar codes may all look the same to people, the data and even the "symbologies" are different. A bar code symbology is sort of like the language of the bar code, and there are many types: UPC, EAN, Code 39 (also called 3 of 9) and many others.