Barcode Scanners are hand-held or stationary devices used for capturing information from barcodes. A barcode scanner consists of a code reader and a decoder. These devices are connected to a computer through compatible ports

The earliest, most basic and cheapest barcode scanners consisted of a fixed light and a single photosensor. Modern barcode scanners have polygonal mirrors and use laser scanning technology. Laser barcode printers have the advantage of reading barcodes from any angle.

Barcode scanners are available in different varieties like hand-held, hands-free, wearable, rugged, scan engines, laser and digital. Pen-wand scanners are the simplest and most portable type of such devices. They have to be kept in direct contact with the barcode and held at a precise angle to interpret the barcodes. Modern day digital cameras have enough resolution to capture both 1D and 2D barcodes.

Barcode scanners can be distinguished as follows:

* LED scanner: Also referred to as CCD scanners, even though the CCD is in fact the photo imaging sensor, not the light source.

* Laser scanner: More expensive than LED scanners but are generally capable of longer maximum scanning distances.

* Imager scanner: These scanners take an image of the linear barcode, generally more rugged as they have no moving parts.

* 2D Imaging scanner: These scanners take a 2D image of the barcode as in a camera and can be used to scan 2D barcode types such as Datamatrix as well as the more common linear barcode types.

* Handheld scanner: With a handle and typically a trigger button for switching on the light source.

* Pen scanner (or wand scanner): a pen-shaped scanner that is swiped.

* Stationary scanner: Wall- or table-mounted scanners that the barcode is passed under or beside. These are commonly found at the checkout counters of supermarkets and other retailers.

* Fixed position scanner: An industrial barcode reader used to identify products during manufacture or logistics. Most often used on conveyer tracks to identify cartons or pallets which need to be routed to another process or shipping location.

* PDA scanner: A PDA with a built-in barcode reader.

The latest in barcode scanner technology is mobile barcode scanners which use color code and mCode (new two-dimensional code format) to scan barcodes.

General purpose barcode scanners are used at checkout counters and hospitals. These are also used to process identification documents. Certain other kinds of scanners, like rugged scanners, are used in harsh or extreme conditions. Of the different barcode scanners, laser scanners and camera scanners are widely used these days. Camera scanners scan and capture the barcode images, which are then processed by sophisticated image techniques to decode the barcode.