An Introduction to Computers and Internet - A Practical Presentation

By Ronald Nsereko

"There is no reason anyone would want a computer in their homes."
Ken Olsen, President and founder of Digital Equipment Corporation (DEC), the producers of the first minicomputer, made this statement in 1977.

Many people would have agreed with Ken at the time but amazingly such a prediction turned out to be entirely incorrect. Computers are now everywhere, and people interact with them in almost every aspect of their daily lives. For this reason, it is necessary for one to have an understanding of a computer's basic operation and usage.

An Introduction To Computers And Internet seeks to give a practical introduction to computers and the internet, as well as a brief look at the history around these innovative creations.

This book was written as a simple, easy-to-reference manual for quick access to information on computers, or information on certain computer operations. The handy table of contents is well detailed to help users swiftly locate their required subject matter.

This book also has multiple images and clear step-by-step procedures on how to perform tasks where needed.
This is the kind of book that should be in every home.
About the Author
Mr Nsereko holds a bachelor's degree in Statistics with Computers. He has taught computers for over a decade and currently works as a web developer and computer programmer based in South Africa.

• Language: English
• Publisher: Ronald Nsereko
• Release date: Mar 5, 2024
• ISBN: 9798224033430

Book preview

Foreword

Computers and the internet have become part of our everyday lives, from staying in touch with friends and family, sharing photographs, booking holidays, and doing shopping online. As technology keeps improving, computers dominate virtually every aspect of our daily existence.

It has therefore become essential to know about computers – basic computer terminology, how a computer operates, and the different computer components. For those who are more curious, it is great to know how the computer came to be and the different trends that have evolved in the computer industry.

Many computer users have learned about computers and how to use them in a very haphazard way, usually by picking up tips and shortcuts from friends and co-workers, learning what they need to know to accomplish the task at hand ‘on-the-go’ – and often forgetting it moments later…

While this approach may keep one functioning, there are often frustrating moments when this system ‘fails’, when you cannot clearly explain something, or you find yourselves with strange results or formatting that seems ‘out of control’.

The goal of this book is to convey information about computers in an organised manner and to act as a reference journal every time you need clarification about a thing or two regarding computers and the internet.

The book is not intended to be very technical, but rather to be informative. It is relevant for all levels; young or old, whether in school or not.

Whether you are a beginner in the world of computers or you have been using computers for many years, there is something for you in this book.

Chapter 1

Overview of computers

Definition

A computer is an electronic device operating under the control of instructions stored in its memory. It can accept data as an input, process the data according to a specified set of rules, produce results, and store those results for future use.

A computer performs the following three operations in sequence:

▸ It receives data and instructions from the input device

▸ It processes the data as per specified instructions

▸ It provides the result (output) in the desired form

Computer terminology

Computer literacy

Also known as digital literacy, computer literacy simply means that a person has current knowledge and understanding of computers and their uses. Because the requirements that determine the level of computer literacy change as technology changes, you must keep up with these changes to remain computer literate.

Computer user

A person who uses a computer – or who uses the information it generates – is called a computer user. This person can be a novice user, someone who has very little understanding of computers, or be an intermediate or expert user depending on the level of knowledge they have about computers.

Expert users include power-users such as programmers, engineers, architects, desktop publishers, web developers, etc.

An official at the South African National Space Agency (SANSA) operating a computer. This person is an example of an expert computer user.

Data

Data refers to unprocessed items (raw facts), which can include text, numbers, images, audio and video. An example is a list of names of students and a list of their marks scored in different subjects. Data is plural; the singular term is datum.

Information

Information is data that has been processed and presented in an organised manner to give meaning and be useful to people. Example: When the names of students are arranged in alphabetical order, and their total and average marks is calculated and presented in a tabular form – this is information.

Information technology (IT)

Information technology, colloquially used as ‘IT’, refers to anything related to computing technology, such as computers, networking, hardware, software, the internet, and the people who work with these technologies. IT encompasses all forms of technology used to create, store, exchange and use information in its various forms (business data, voice conversations, stills images, motion pictures, multimedia presentations, and other forms of data). It is a convenient term for including both information and computer technology in the same word.

Many companies now have IT departments for managing its information, computers, networks and other technical areas of the businesses. IT jobs include computer programming, network administration, computer engineering, web development, technical support and many other related occupations.

Types of computers

The personal computer (PC)

A PC is a general-purpose computer that uses a microprocessor. It is designed for individual use by a person in an office, at home, or at school for various applications such as word processing, data management, financial analysis, computer games, etc. The acronym ‘PC’ is also a generic term for personal computers using the Microsoft operating system (OS).

Today, the world of personal computers is principally divided between the Apple Macintosh (MACs) and PCs (computers running on Windows).

The principal characteristics of personal computers are that they are single-user systems. However, they can be linked together to form a network.

Personal computers can be desktop or laptop computers.

Desktop computers

A desktop computer is a personal computer in a form intended for regular use at a single location only – usually a desk or a table – due to its size and power requirements.

Laptop computers

A laptop or notebook is a portable personal computer of fairly small size suitable for mobile use. In the past, there was a difference between laptops and notebooks, but nowadays the distinction has gradually fallen away.

Laptop computers have an L-shaped design. The screen can be lowered and closed to allow for easy transportation of the device. Laptops provide users with the ability to run the machine using an internal battery or an outside power supply.

The primary characteristic that attracts users to laptops over desktops is their portability. While portable computers used to be significantly slower and less capable than desktop computers, advances in manufacturing technology have enabled laptops to perform nearly as well as their desktop counterparts.

The convenience of laptops often comes at a price. Most laptops cost much more than a similarly-equipped desktop model with a monitor, keyboard, and mouse. Furthermore, working long hours on a laptop with a small screen and keyboard may be more fatiguing than working on a desktop system. Therefore, if portability is not your requirement in a computer, you may find better value in a desktop computer than a laptop.

Laptops can be used virtually everywhere.

Tablet computers

A tablet computer – or mostly referred to simply as a tablet – is a mobile computer with display, circuitry and battery in a single unit. Tablets come equipped with sensors, including cameras, a microphone and a touchscreen. Finger or stylus gestures substitute for the use of a traditional computer mouse and keyboard.

Tablets may include physical buttons (for controlling basic features such as speaker volume and power) and ports (for network communications and charging the battery). They usually feature on-screen, pop-up virtual keyboards for typing. 

Different view of a tablet.

Workstation

A workstation is a computer intended for use by one person, but with a much faster processor and more memory than an ordinary personal computer. Workstations are designed for powerful business applications that do a large number of calculations or require high speed and graphical display capabilities. The advent of computer aided drawing (CAD) was one reason for their initial development.

An early workstation was introduced in 1987 by Sun Microsystems. Workstations introduced in 1988 from Apollo, Ardent and Stellar were aimed at 3D graphics applications. The term workstation is sometimes also used to mean a personal computer connected to a mainframe computer, to distinguish it from ‘dumb’ display terminals with limited applications.

Because workstations often work together, they are commonly networked, i.e. linked together. This allows them to send files back and forth over the network, which is important for various types of media production. For example, a user at a photo-editing workstation may prepare images to be used in a video clip. Once the images are ready, he may send them to another user at a video-editing workstation where they are incorporated into the video. Once the video has been put together, the video file may be sent to another user at an audio production workstation where the soundtrack and other sound effects are added.

Workstations are usually used for applications that require extended computer resources.

Server

A server is a computer that provides data to other computers over a network.

Many types of servers exist, including web servers, mail servers, and file servers. Each type runs software specific to the purpose of that server. For example, a web server may run Apache HTTP server or Microsoft IIS software. Both provide access to websites over the internet. A mail server may run a programme like Exim or iMail, which provides SMTP services for sending and receiving email.

While server software is specific to the type of server, the hardware is not as important. In fact, a regular desktop computer can be turned into a server by adding the appropriate software. Most large businesses, however, use rack-mountable hardware or computers designed specifically for server functionality.

An example of a computer specifically designed to be a server.

Mainframe computer

Mainframe computers (sometimes referred to as ‘big iron’) are ultra high-performance computers used primarily by corporate and governmental organisations for critical applications such as bulk data processing, process control, industry and consumer statistics, enterprise resource planning and financial transaction processing.

The term originally referred to the large metal cabinets called ‘main frames’ that housed the central processing unit and main memory of early computers. Later, the term was used to distinguish high-end commercial computers from less powerful units.

Mainframes are super-reliable because a lot of circuitry is designed to detect and correct errors. Every sub-system may be continuously monitored for potential failure, in some cases even triggering a list of parts to be replaced at the next scheduled maintenance. As a result, mainframes are incredibly reliable with mean time between failure (MTBF) of up to 20 years. This enables these machines to run uninterrupted for decades.

A modern mainframe computer.

Supercomputers

A supercomputer is a term given to computers at the top of modern-day processing capacity, particularly with regards to its speed of calculation, which can happen at speeds of nanoseconds. These are the fastest types of computers. Supercomputers are very expensive and are employed for specialised applications that require immense amounts of mathematical calculations. Examples of its use are weather forecasting, animated graphics, fluid dynamic calculations, nuclear energy research, and petroleum exploration.

The term is commonly applied to the fastest high-performance computers available at a given time. Current personal computers are more powerful than the supercomputers of just a few years ago.

The main difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programmes as fast as possible, whereas a mainframe uses its power to execute many programmes concurrently.

Summit, or OLCF-4: In November 2019, it was the fastest supercomputer and the fifth most energy-efficient in the world with a measured power efficiency of 14.668 gigaFLOPS/watt. Summit is the first supercomputer to reach exaflop speed (a quintillion operations per second).

Wearable computers

Wearable computers, also known as body-borne computers, or wearables, are computer-powered devices or equipment that can be worn by a user in the form of clothing, watches, glasses, shoes, and similar items.

Wearable computing devices can range from providing very specific, limited features like heartrate monitoring and pedometer capabilities to advanced smart functions and features similar to those of smartphones. 

Wearable computers have the ability to multi-task. It is not necessary to stop what you are doing to use the device. It is augmented into all other actions. These devices can be incorporated for the user to act like a prosthetic (an ‘extension’ of the user’s body, if you like) to allow them to perform tasks they never could do using only their mind and/or body.

The Apple Watch is a computer in the form of a wristwatch. It incorporates fitness tracking and health-oriented capabilities with integration of its iOS and other Apple products and services. It operates primarily in conjunction with the user’s iPhone for functions such as configuring the watch, calling and texting, and syncing data with iPhone apps, but can independently connect to a Wi-Fi network for certain tasks.

Embedded computers

An embedded computer is a special-purpose computer that functions as a component in a larger product. Embedded computers are everywhere — at home, in cars, and at work. The following list identifies a variety of everyday products that contain embedded computers:

▸ Consumer electronics: Mobile and digital telephones, digital televisions, cameras, video recorders, DVD players and recorders, answering machines

▸ Home automation devices: Thermostats, sprinkler systems, security monitoring systems, appliances, lights

▸ Automobiles: Anti-lock brakes, engine control modules, airbag controllers, cruise control

▸ Process controllers and robotics: Remote monitoring systems, power monitors, machine controllers, medical devices

▸ Computer devices and office machines: Keyboards, printers, fax and copy machines

Because embedded computers are components in a larger product, they usually are small and have limited hardware. These computers perform various functions, depending on the requirements of the product in which they reside. Embedded computers in printers, for example, monitor the amount of paper in the tray, check the ink or toner level, signal if a paper jam has occurred, and so on.

An example of a medical device that has a computer embedded inside it.

Anatomy of a computer

To explain the anatomy – or composition – of a computer, we can refer to the basic block diagram below. This composition of the flow of information holds true for all types of computers, whether personal computers or supercomputers. The fundamental principle working of all computers is the same. What makes them different is the amount and complexity of hardware and/or software they consist of.

Basic composition of a computer. The arrows represent the flow of data/information.

A computer is basically made up of a processor, its primary memory, input devices, output devices and secondary storage devices. Data is entered through input devices like the keyboard, mouse, touchscreen, microphone, etc. These input devices convert data and programmes into the language that the computer can process and send it to the memory, which is known as RAM. Data received from the input devices is processed by the central processing unit (CPU), usually called a processor. The CPU controls and manipulates the data to produce information. The processed data is either stored in the memory for other processes, sent to the output device, or saved in secondary storage as per the command given by the user. Output devices like the monitor translate the processed information from the computer into a form that humans can understand. Secondary storage devices like hard disks store the information for future use and can retrieve it into primary memory when required.

Processor

In a computer, data and instructions are processed in a control centre that converts the data inputted into information. This control centre is called the central processing unit (CPU). It is a highly complex, extensive set of electronic circuitry that executes stored programme instructions. All computers, large and small, must have a central processing unit.

The CPU consists of two parts, the control unit (CU) and the arithmetic/logic unit (ALU). Each part has a specific function.

An Intel Core i7 4770K processor. Intel is the largest manufacturer of processors and computer chips.

The ALU is the unit in the processor where all arithmetic operations (addition, subtraction, multiplication and division) and logical functions such as true or false, male or female are performed. Once data is fed into the main memory from input devices, it is held and transferred as needed to the ALU, where processing takes place. No process occurs in primary storage. Intermediately generated results in the ALU are temporarily placed in memory until needed at a later time. Data may move from the primary memory to the ALU and back again to storage many times before the processing is finalised.

The control unit (CU) acts as a central nervous system. It ensures that information is stored correctly, that programme instructions are followed in a proper sequence, and that data is selected from the memory as necessary. It also coordinates all the input and output devices of a system to insure that instructions are correctly performed.

Memory

Memory is also known as primary storage, primary memory, main storage, internal storage, main memory, and RAM (Random Access Memory). All