FAQ# 1072:

Which barcode scanner interface should I buy?

Answer

Generally speaking, you should buy a USB barcode scanner. These scanners function more or less as USB keyboards: Your computer (most scanners are compatible with both Windows and Mac OS, as well as Linux) will recognize the device as a USB human interface device (the same as it recognizes a keyboard), and scan data will be transmitted through the keyboard buffer.

If that is all a bit complex, think of it this way: A USB barcode scanner will work in any situation where a keyboard would work. If you can enter a barcode with your keyboard, you can enter it with a USB barcode scanner.

PS/2 barcode scanners are essentially the same as USB scanners, except that they use PS/2 keyboard ports. Most new computers do not come equipped with PS/2 ports, but, as many computers in the point-of-sale (and point-of-service) world are not what anyone might call "new," you may desire a PS/2 scanner. One notable difference between PS/2 and USB scanners is that PS/2 scanners also offer an additional PS/2 keyboard port, so that, if you are using a PS/2 keyboard, you do not need to stop using it when you attach a PS/2 barcode scanner.

The other once-common scanner interface -- now very much less common than it was -- is serial, or RS-232. These scanners interface with computers in an entirely different manner. Unless your software specifically requires a serial scanner, it is quite recommended that you avoid the interface altogether.