INFO TECH

What is a computer

What is a computer

An electronic device that accepts, processes, and stores data for later use or sends out data as information.

Types of computers

Supercomputer, mainframe, desktop, mobile devices, embedded

Embedded

A type of computer that is integrated into other devices or systems.

Advantages of using a computer

Consistency and accuracy of results provided, enhanced storage capabilities.

Disadvantages of using a computer

High initial setup cost, potential for compromised security and data integrity.

Hardware

Any physical component of a computer system, including internal parts.

Input

The act of accepting data from the outside world.

Input device

A device responsible for getting data into a computer.

Processing

The act of transforming data into information that will be useful to the user.

Output

The act of presenting information to the user.

Output device

A device that retrieves processed data from the computer and presents it to the user.

Storage

The act of holding data, program instructions, and information for later use.

Memory

A component that enables a computer to temporarily store instructions and data.

Central Processing Unit (CPU)

The brain of the computer that manages and orchestrates how the computer functions, consisting of the Control Unit (CU) and Arithmetic Logic Unit (ALU).

CU

Executes software instructions and guides the flow of data.

ALU

Responsible for performing calculations and logical operations.

Peripheral devices

Devices located outside the CPU but controlled by it.

Primary storage

The component of the computer that holds data, programs, and instructions currently being used.

Secondary storage

Non-volatile devices for storing data outside of a computer's main memory.

Main memory

Random Access Memory (RAM), a type of computer memory that serves as the short-term working memory of a computer.

Dynamic RAM

A type of RAM that requires constant refreshing and is volatile.

Static RAM

A type of RAM that does not require refreshing and is faster but more expensive than dynamic RAM.

ROM

Read Only Memory, a type of non-volatile memory that stores permanent instructions.

PROM

Programmable Read Only Memory, a type of ROM that can be modified once by the user.

EPROM

Erasable Programmable Read Only Memory, a type of ROM that can be erased using ultraviolet rays and reprogrammed.

EEPROM

Electrically Erasable Programmable Read Only Memory, a type of ROM that can be erased and reprogrammed multiple times by applying an electrical voltage.

Storage unit

A unit of measure used to indicate the amount of information that can be saved on a computer.

Cloud storage

The process of storing data in an online space maintained by a hosting company, accessible with an internet connection.

Local storage

The process of storing digital data on physical storage devices such as hard disk drives and external storage devices.

Software

Programs executed by the computer hardware.

Types of software

System and application

System software

Software used to operate and maintain a computer system, including the operating system, utility programs, and language translators.

Operating system

A set of programs that governs the operation of the computer and provides user interfaces, security management, file management, resource management, memory management, and process management.

System utility

A specialized program that assists in maintaining and improving the efficiency of a computer system, such as backup, defragmenter, disc error checker, disc cleanup, and antivirus.

Application software

Programs that help the user perform specific tasks, including general-purpose software, customized software, and specialized software.

Data

Raw, unprocessed facts without context, such as plain numbers or text.

Information

Meaningful knowledge derived from processed and organized data.

Data processing

Turning unorganized data into organized, useful information.

What is a file

A FILE is a container in a computer system for storing information, data or programs. 

File access methods

Serial, sequential and random access

Serial

Data is stored in the file in the order in which the data was written to the file. Usually used on secondary storage devices.

Sequential

Data is stored in a particular order/sequence. 

Random access

 Allows a user to go straight to the data they are looking for

Archiving

Storing files that are not accessed frequently on another storage device.

System Backup

A copy of all the files on a computer system that can be used to restore the whole computer after a case of hardware failure or data loss.

Backup

The copying of a file to a separate, removable storage drive in case the original data is destroyed. 

Document

A written or digital file that is used to collect and store data. 

Source documents

Documents containing data for input into an information processing system.

Human-readable document

A document that can be read naturally by humans but not readily accepted by computers.

Machine-readable document

A document that can be readily processed by computers, such as items within a barcode.

Turn-around document

A computer-generated form that is filled out, sent out, and returned to the computer.

Verification

Double-checking for errors with data that has already been entered.

Proofreading

Visually checking the source document against data that has already been input by another entry clerk.

Double data entry

Entering data twice for comparison.

Validation

A checking process in a program aimed at determining if the entered data is genuine.

Data type check

Validating the data based on its expected type.

Presence check

Ensuring that the data is present and not missing.

Check digit

A digit added to a number for error detection.

Range check

Verifying that the data falls within a specified range.

Consistency check

Ensuring that the data is consistent with other related data.

Length check

Verifying that the data has the correct length.

Reasonableness check

Checking if the data is reasonable or within expected limits.

Format check

Validating the data based on a specified format.

Troubleshooting

a systematic approach to find and correct issues with computer and software systems.

System specifications [SPECS]

Technical descriptions of the computer’s components and capabilities

PROCESSING SPEED

How quickly a processor operates . Processing speed is measured in Gigahertz (Ghz)