Question

when is a bar code reader used for input and how?

Answer 1

Barcode readers are used for giving a unique identity to a specific product.
A barcode reader reads the barcode and retrives the data from the database (previously added data) and gives the information of the product.

Answer 2

board card reader is a handle or stationary input device which capture and read information contained the board code barcode of barcode reader consists of Clans light light source and light sincere which translate the optical input into electric ones