Barcode readers are also known as price scanner, point-of-sale (pos) scanner or barcode scanners. They are generally seen in supermarkets being used by sales person for price, product detection. It is a handheld stationary input device which is used to capture and read information contained in a barcode.
A barcode reader has a lens, light source and a light sensor used to translate light impulses into electrical impulses. It captures and translates the barcode into numbers and/or letters. Then, the data is sent to a computer where an application provides the meaning of the data. They can be connected via a USB port or PS/2 port using a wedge or a splitter. IR, RF, Bluetooth, O-R, and other types of wireless connection is also possible with the barcode reader.
Nowadays, smart phones come with built-in scanners embedded in their cameras. You can either install the software or the software may be pre-installed. The most common types of barcode which are input and process in this manner are Universal Product Code (UPC), Quick Response (QP) and 2D matrix barcodes.