Basic IT concepts

and IT orientational training

with Tests for practice


  1. Basic IT concepts
    • Topic map of the main concepts
    • Index of basic IT terms
    • Lexicon of basic IT terms
    • Useful tips for language learners
    • Tests for practice
      • Test settings
    • What is a computer?
      • Digital computer
        • What is a computer?
        • What does digital mean?
        • What are the most important data types?
      • Computer systems
        • What are the main components of a computer system?
        • What can be the benefit of using more than one computers at the same time?
        • In what forms can computers work together?
      • Computer hardware
        • What are the basic parts of the central unit of a modern computer?
        • What is the main function of the ALU and the CU?
        • What kind of peripheral devices do you know?
      • Early computers
        • What are the early computers meant for?
        • When were the ENIAC completed?
        • What lead to the Digital Revolution of our times?
      • Computer software
        • What is the main role of instructions in the computer?
        • What is software made up of, and what do programs consist of?
        • What is the function of the operating system?
      • Computer applications
        • What kind of special-purpose devices use computers as control systems?
        • Why can personal computers be considered as general-purpose devices?
        • What is the most important feature of the Internet?
      • Tests for practice

Recommended reading:
Computer Basics - Tutorial (2023-02-14)
Wikipedia (2023-02-08)

Topic map of the main concepts

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Index of terms

Lexicon of basic IT terms


A digital computer is a digital electronic machine that can be programmed to carry out sequences of operations automatically.

Related terms

digital;* electronic;* program;* operation;*


machine, device; ≼instrument, tool, appliance, utensil; ≺equipment, apparatus;

carry out, perform (task, exercise, action, operation, instruction, program etc.); ≼ fulfil (task); conduct (exercise, operation); execute (instruction, program); run (program); ≺ do (task); take (action);


[adj+computer] digital ~; electronic ~;

[vt+computer] program ~;

[computer+vt] ~ carry out (operations);

A computer is an electronic device that manipulates information or data.

Related terms

data;* information;

A computer is an electronic device designed to accept data, perform prescribed mathematical and logical operations at high speed, and display the results of these operations.

A digital computer is a universal electronic data processing equipment.

Related terms


A computer is an electronic machine that can store and deal with large amounts of information.

A computer is an electronic machine that can quickly make arithmetical calculations, store, rearrange, and retrieve information, or control another machine.


[computer+vt] ~ make (calculations); ~ store (information); ~ rearrange (information); ~ retrieve (information); ~ control (machine);

ENIAC was the first programmable, electronic, general-purpose digital computer which was completed in 1945. (Wikipedia)


[adj+computer] programmable ~; general-purpose ~;

The main hardware units of a von Neumann computer are a control unit, an arithmetic and logic unit (ALU), a main memory, and input and output facilities.

Related terms


This tutorial will help you understand how computers work and how to use them.


[computer+vi] ~ work;
[vt+computer] use ~;

If you are just looking to learn more about how computers work, you will find all of the information you need in this tutorial.

We'll talk about how to set up a new computer, the difference between hardware and software, and so on.

Related terms

hardware;* software;*


set up, put together, assemble;

You can use a computer to do many things, for example to type documents, send emails, browse the Web, create and edit spreadsheets, presentations and even videos, play games, and so on.

After we have bought a new computer, the first thing we have to do is to set up and configure it.


[vt+computer] set up ~; configure ~;

Everything you do on your computer will rely on both hardware and software.


rely on, depend on; ≼be based on; ≺need, require;



The address of a specific data item refers to its location within the main memory of the computer.

addressing scheme

Addressing schemes are the wide variety of schemes developed in order to provide compact or convenient address references to the operands of the instructions available for a given processor.


An algorithm is a prescribed set of well-defined instructions or statements for the solution of a given problem in a finite number of steps (e.g. the performance of a calculation).

The instructions or statements of the algorithm are usually encoded in a selected programming language.

application program

An application program is a computer software package that performs a specific function directly for the end user or, in some cases, for another application.

Examples of application programs are web browsers, computer games, word processors, spreadsheet applications, various kinds of presentation software, graphics software, and so on.


backward compatibility

Backward compatibility is the ability of a later and more capable computer to use a hardware unit developed for, or to directly execute a program written for an earlier and less capable computer.


backward compatibility; ↭ upward compatibility;*



The chipset is a set of integrated circuits that manages the data flow between the microprocessor, the memory, and the peripherals on the motherboard of the microcomputers.


The cloud or cloud computing is a metaphor for internet-based computing services that allow users to store, access and process data over the Internet instead of using the local computer's resources.

In the tutorial we'll also explore operating systems, applications, the Internet, the cloud, and a whole lot more.


A computer cluster is a set of computers that work together so that they can be viewed as a single system.

computer system

A computer system is a nominally complete computer that includes the core hardware, peripheral equipment, the operating system and the application software needed and used for full operation.



Data is stored information which is usually organized in a structured way.

Related terms


Organized data, especially when they appear in the form of models, provide an abstract representation of reality.

Related terms


The computer has the ability to store, retrieve, and process data.


[computer+vt] ~ process (data);

[vt+data] store ~; retrieve ~; process ~;

Data are entered by terminal for immediate processing by the computer.

Related terms



[vt+data] enter ~;

data processing

Data processing (DP) is the process of selecting and operating on data to produce useful information, e.g. by way of sorting and/or organizing data files.

Related terms

data;* information;*

data representation

Data representation is the coding rules and internal format applied to the different classes of primitive and complex data types defined in a computer system.

Related terms

data type;* coding rules; format;

data type

Data type defines the way a particular data item or unit is represented and interpreted by the computer.

Examples of primitive data types are integers, real numbers, logical values and characters.

Examples of complex data types are strings, arrays, and database records.


Colloquially, a database is a collection of data on some subject however defined, accessed, and stored within a computer system.

Strictly, a database is a structured collection of data held within a computer system using the facilities of a database management system or DBMS.


A digit is any of those one-character symbols of the positional number systems that are used for representing numbers.

In the binary number system 0 and 1 are binary digits or bits.

In the hexadecimal number system 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and A, B, C, D, E, F are hexadecimal digits.


A digital device uses sequences of digits to represent data that are used during its operation.

Related terms

digit;* data representation;*

A modern computer is a digital electronic machine that can be programmed to carry out sequences of arithmetic, logical or other type of operations using binary representation of data.

Related terms




All digital computers today are built up from electronic circuitry.

An electronic circuit establish a connection between electronic components that perform a specific function.


grid computing

Grid computing is the use of widely distributed computer resources to reach a common goal.



Computer hardware is the physical portion of the computer system including any part of the computer that has a physical structure.


hardware;* ↭ software;*

The hardware of a personal computer includes all of the computer's internal parts and external components, such as the motherboard, processor, main memory etc., and the monitor, keyboard, mouse etc., respectively.



In a technical sense, information is retrieved data which can be used for a specific purpose.


An instruction is the description of an operation that is to be performed by the processor of a computer.

Related terms


An instruction is a command to the processor of a given computer system.

An instruction is normally made up of a combination of an operation code and the specification of the operands that present or refer to the data upon which the operation is to be performed.

instruction set

An instruction set is the of instructions that a processor of a given computer system is capable of performing.

Related terms


The instruction set of a given computer system includes the list of all the operation codes, the specification of the operands, and the permitted addressing schemes pertinent to each instruction.



A motherboard (or mainboard) is the main printed circuit board (PCB) in general-purpose computers.

The motherboard (MB) allows communication between many of the crucial electronic components of the computer system (e.g. the CPU, main memory etc.).



A computer network is a number of computers, terminals and peripherals connected together to allow communications between each.



An operation is any procedure, such as addition, multiplication, set union, conjunction etc., that generates a unique value according to mechanistic rules from one or more given values as arguments.

The fundamental operations of arithmetic are taken to be addition, subtraction, multiplication, division and exponentiation.

The operation code (or op code) is usually the first portion of the instruction that specifies the operation to be performed by the computer.

Related terms


Each statement is composed of a predefined sequence of given operations to be performed.


consist of; be composed of; be made up of; be build up from;



A computer program consists of a given set of instructions or statements that can be executed by a computer in order to carry out a clearly defined task.

Related terms

instruction;* statement;

Computer programs formally describe and implement algorithms in a formal notation by way of one of the programming languages supported by the software of the computer system.

A program written in a high-level programming language is a sequence of statements.

The programs, especially the application programs enable computers to perform a wide range of tasks.

A program for a von Neumann computer consists of a set of instructions that are examined and executed sequentially, that is, one after another.

Related terms


An instruction is the smallest unit of a program which is executed directly by the processor.


relational database

A relational database applies a data model that views data as a collection of distinctly named two-dimensional tables some of which can be joined together to produce larger tables.

In the relational database model the cells within a particular column of a table always contain atomic or single data items which must be all of the same type.



Computer software is the intangible portion of the computer system consisting of all the programs that can be executed by the computer in order to produce a desired behaviour from the computer.


hardware;* ↭ software;*

Computer software tells the hardware what to do and how to do it by giving detailed and precise instructions to the hardware units concerned.


instruction, statement; ≼ program;* ≺ software;*

The software of a computer includes a set of cooperating programs that control the operation of the computer hardware, such as the operating system, drivers, utilities, software development environments, application programs etc.


Spreadsheets are interactive tables that contain selected pieces of information in their cells including numerical data, formulas, texts and other types of data.

Interactive tables can be manipulated by spreadsheet programs which store the data of the tables in files with dedicated extensions (e.g. xls or xlsx).



A computer terminal is a simple data input and/or output device that is connected to a usually remote computer.

Related terms

input; output

Using a terminal, the user can control a remote computer interactively by typing commands through a text-based interface to the computer.

Colloquially, a terminal can be considered as a stand-alone keyboard with a connected monitor.


upward compatibility

Upward compatibility is the ability of a new hardware unit developed for, or of a computer program written for a later and more capable computer to be used, or to be directly executed by an earlier and less capable computer.


upward compatibility; ↭ backward compatibility;*


word processor

A word processor is a program that enables its users to manipulate electronic documents with maximum flexibility so that they can easily compose, format, edit, store, or even print their documents.

MS Word is a versatile and widely used word processor which is very popular nowadays in many workplaces, for example in schools, colleges, universities, hospitals, and offices.

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Borowski, E. J. – Borwein, J. M. 1989. Dictionary of Mathematics. London – Glasgow: Collins.

Burrell, Mark 2017. Fundamentals of Computer Architecture. Bloomsbury. (2023-05-24)

Collin, S. M. H. 2002. Dictionary of Information Technology. London: Peter Collin Publishing.

Collins COBUILD English Dictionary. London: HarperCollins Publishers. 1997.

GFC Global: Computer Basics.
Computer Basics - Tutorial (2023-02-14)

Gunton, Tony 1992. Dictionary of Information Technology and Computer Science. London etc.: Penguin Books.

Illingworth, Valerie – Pyle, Ian 1996. A Dictionary of Computing. Oxford – New York etc.: Oxford University Press.

Oxford Collocations Dictionary for Students of English. Oxford University Press, 2002.

Stallings, Warren D. – Hutchinson, Sarah E. – Sawyer, Stacey C. 1988. Computers. The User Perspective. St. Louis – Toronto – Santa Clara: Times Mirror – Mosby College Publishing.

Random House Webster's Unabridged Dictionary. New York: Random House Reference, 2009.

Roget's Thesaurus of English Words and Phrases. (ed. by Kirkpatrick, Betty) Penguin Books, 1987.

TechTarget - Software Quality (2023-03-23)

Wikipedia (in English) (2023-03-23)

Boda István, 2023.