For simple applications, the corded barcode scanner is all that's required for you to begin
  reaping the benefits of increased speed and accuracy in scanning barcodes. In all retail and
  most industrial environments product barcodes can be found on most items shipped from   vendors.

  Most companies now have computer software that requires an operator to enter the UPC or SKU   number into the system, which a corded scanner can accomplish on a ‘plug and play’ basis.

  Even the simplest and most basic corded barcode scanner is programmable. The programming
  of the unit is stored in the firmware within the device itself. In most cases, the scanner is   programmed by scanning specific set-up barcodes from the manual in a specific order, although   most manufacturers now have software tools available to do that part for you - all you have to do is   programme the rules that you want the scanner to follow.

  Programming options include how the device will perform. On most corded scanners you can set   the interface, when the scanner light turns on and off, and the volume and duration of the beep   indicating a good read.

  The most common barcode scanner sold is the "wedge" or "corded" scanner. These scanners
  can be used to scan EAN 13, Code 39 and now on certain models the new 2D barcodes.