A barcode can be read by a handheld device or by a fixed position scanner or at a remote distance, for example on a moving conveyor belt.
Working with Datalinx Computer Systems and their warehouse management solutions they use a variety of scanners but the principle is the same, push the scanning button on the device and a red light shines in a straight line and when it encounters the barcode that you are ‘carefully’ aiming it at it reads the ‘printed’ code (or gaps between the dark lines). It then checks with your warehouse management system and translates the code into human readable data which if your system is set up correctly should be a recognisable reference and match the item you’ve just scanned. Usually this happens in a lot shorter time than it just took you to read this!
All barcode scanners work on the same principle
1) Illuminate the code
2) Capture the reflection
3) Decode what has been captured to make up the data