There are various types of files used for storing data needed for processing, reference or backup. However the main common files include:
Master files, Transaction, Reference, Backup, Report and sort file.
This file is normally used for reference or look-up purposes. Look up information is that information which is stored in a separate file but is required during processing.
A backup file is used to hold copies (backups) of data or information from the computers fixed storage (hard disk)
A report file is used to store relatively permanent records extracted from the master file or generated after processing.
A sort file stores data which is arranged in a particular order
B. Of the above files, which file can be used:
i. In a supermarket to fetch the price of a commodity from the master file
ii. In a supermarket to update the master file
iii. In a bank to extract and store some important records from the master file
iv. In a bank to arrange records of customers according to their bank deposits
v. By the government to a keep copy of listed employees in the master file who are about to retire in one year time