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Data processing security is an appropriate technical and organizational measures to protect data against accidental or unlawful destruction or accidental loss or alteration, or unauthorized disclosure or access, or other unauthorized processing.
i)Blocking attacks from unauthorised users or hackers.
ii)Preventing malware infections and stopping viruses stealing data.
iii)Prevents data loss through corruption of files or programming errors.
i)Hierarchical data model.
ii)Relational model.
iii)Network model.
iv)Object-oriented data model.
Relational model- this is the most common model, the relational model sorts data into tables, also known as relations, each of which consists of columns and rows. Each column lists an attribute of the
entity in question, such as price, zip code, or birth date. Together, the attributes in a relation are called a domain. A particular attribute or
combination of attributes is chosen as a
primary key that can be referred to in other tables, when it’s called a foreign key.

Mobile phone:-Mobile phone also known as cellular phone , cell phone and a hand phone is a device that can make and receive telephone calls over a radio link while moving around a wide geographic area. it does so by connecting to a cellular network provided by a mobile phone operator, allowing access to the public telephone network

Vending machine:-A vending machine is a machine which dispenses items such as snacks, beverages, alcohol, cigarettes, lottery tickets, cologne, customer products and even gold and gems to customers automatically, after the customer inserts currency or credit into the machine.

Cash Register:-A cash register also referred to as a mechanical or electronic device for calculating and recording sales transactions and an attached cash drawer for storing cash. The cash register also usually prints a receipt for the customer

Fax machine:-Fax machine also known as facsimile or tele copying, is the telephonic transmission of scanned printed material, both text and images, normally to a telephone number connected to a printer or other output device. The receiving fax machine reconverts the coded image, printing a paper copy.

Point of sale machine:-A point of sale/service (POS)machine is used to conduct retail transactions. It can provide many services, including credit card processing, check reading and cash transactions, depending on the model.


(i)Data models can facilitate interaction among the designer, the applications programmer and the end user.

(ii)data models can greatly improve user experience and increase the efficiency of data utilization.

(iii)Data models make data statistics more consistent and reduce the possibility of computing errors

(iv)Data models can significantly reduce unnecessary data redundancy, reduce the storage and computing costs for a big data system

A standard data model or industry standard data model(ISDM)is a data model that is widely applied in some industry and share amongst competitors to some degree. They are often defined by standards bodies, database vendors or operating system vendors

(In Tabular form)
(i)Preventive maintenance is the act of a regularly scheduled check of the computer hardware or software to help ensure it continues to operate properly.
Corrective maintenance is a form of maintenance that is performed after a fault or problem emerges in the system, with the goal of restoring operability.

(ii)preventive maintenance in computer system is done frequently(preventing problem)
Corrective maintenance in computer system is done randomly (when problem occurs)

NAPIER BONES:-John napier ( 1550 – 1617 ), a Scottish mathematician , is mostly known for his invention of logarithms, a device that revolutionized calculation by reducing difficult and tedious multiplication to addition of table entries. In 1614 john Napier made a more sophisticated computing machine called the napier bones. This was a small instrument made of 10rods on which the multiplication table was engraved. It was made of the strips of ivory bones, and so the name Napier bones. This device enable multiplication in fast manner, if one of the numbers was of one digit only.

JACQUARD LOOM:- In 1801 , Joseph Marie Jacquard , a French textile weaver , invented a power loom with an automatic card reader. This power loom used a series of cards with holes punched at different position. To automatic the weaving process, these cards were placed between the needles and the thread, therefore creating different patterns. The presence or absence of a hole in a punched card representing the two digits of the binary system, which is the base for all modern digital computer.