Computer Science for IGCSE & O level - Hardware (Section 4 - No. 16)
What is the function of the 'key field' in the context of barcode systems at the checkout, as per the provided text?
To store the price of the item.
To uniquely identify the stock item in the database.
To calculate the total sale price.
To determine if the item needs to be reordered.
Explication
The text states that the key field uniquely identifies each stock item.