How do you use a handheld barcode scanner?

Many handheld barcode scanners use a gun-styled design with a pistol grip. With these types of barcode scanners, the scanner is activated by pulling and holding the trigger on the device's grip. Other barcode scanners resemble cellphones or attachments for vacuum hoses, in which case there may be a dedicated scan button that must be pressed to start the scan. Other scanners may be constantly active once turned on, in which case it is sufficient to simply point the scanner at a barcode until the barcode registers.

Many people and businesses use cell phones in lieu of dedicated handheld barcode scanners, particularly for scanning the 2D barcodes known as QR codes. While interfaces for barcode scanning apps vary from program to program, the principles of use are often similar to that of a handheld barcode scanner, though most apps use a phone's camera to capture an image of the barcode rather than scanning it with a laser or other light source, as dedicated scanners do.