A barcode reader (or barcode scanner) is an electronic device for reading printed barcodes. The scanner reads the barcode and transfers this information to, to a program on the computer. Most scanners use a USB connection. The barcode characters are then received by the host computer as if they came from its keyboard decoded and converted to keyboard input within the scanner housing. This makes it easy to interface the bar code reader to any application that is written to accept keyboard input.

There are several types of scanners {this is only a partial list)

• Handheld scanner - with a handle and typically a trigger button for switching on the light source.
• Fixed position scanner -these labels are usually very color intensive and graphically enhanced.
• Information on label - an industrial barcode reader used to identify products during manufacture or logistics. Often used on conveyor tracks to identify cartons or pallets which need to be routed to another process or shipping location. Another application joins holographic scanners with a checkweigher to read bar codes of any orientation or placement, and weighs the package. Systems like this are used in factory and farm automation for quality management and shipping.
• PDA scanner - A PDA with a built-in barcode reader or attached barcode scanner.

Modern handheld barcode readers are operated in wireless networks according to IEEE 802.11g (WLAN) or IEEE 802.15.3 (Bluetooth). However, such configuration limits the time of operation from battery or rechargeable battery and required recharging at least after a shift of operation.