INTRODUCTION
The use of computer and related devices in our daily activities today has become very frequent. Most people use computer without even realizing it’s a computer as most people limit a computer to just a desktop or laptop, whereas most devices today are work based on the algorithm and structure of a computer.
In general computers are made to solve human problems as everyday human problems arise that needs urgent and immediate solution. Some computers are designed to handle and solve different kinds of problems while others are designed to solve only one problem.
DEFINITION
A concrete definition of computer that can cover all the types of computers may be rare to find as computers are evolving and invading different areas and aspects of life. There are different definitions used to describe or define a computer by different authors due to different conditions and criteria. For the purpose of this guide to practical computer, a computer could be defined as an electronic device that accepts raw facts as data, process such data by series of instructions and give out desired result as information. There could be other definitions such as an IPO machine which means Input process output.
Data – The word data is a commonly used word in computer as the general operation of a computer depends on data processing. Data is referred to as a raw fact which has no meaning unless worked upon (processed). A collection of names phone numbers and address is an example of data. A key press by a user on the keyboard is also data sent to the computer.
Processing – This is the action of working on collected data to produce meaningful result or desired output. When a user press a key on the keyboard, the computer process such action as data gives a result by executing a command assigned to that key. Similarly collecting of people’s data can be of more use if it’s written down orderly in ascending or descending order arranging their names and phone numbers distinctly and orderly; this action can be termed processing.
Information – This is the result of processed data which is now useful to almost anyone as it is now organized orderly. By pressing P on the keyboard the computer prints out P on the monitor.
The terms data, processing and information are frequently used and forms the Basis of the concept of computer. The use of the word data and input (a noun) are most times used interchangeably; and output could also be referred to as the result or information.
CLASSIFICATION
The computer is classified into different categories with based their distinct features and mode of operation. This classification is based on the following
- Purpose
- Type
- Size and speed
- Generation or year of invention
Purpose: By purpose computers are classified into their distinctive purposes or task they perform. Some computers are designed for calculation while others are design for driving planes and others can perform multiple task i.e they are created for more than one purpose. Thus there are two classes, namely;
- General purpose computers
- Special or specific purpose computers
General purpose computers are computers that has the ability and architecture to handle multiple tasks or functions. They are design to solve different problems. A laptop computer which is able to access internet, process word documents and run mathematical operations is a typical example of a general purpose computer. Examples of general purpose computer include desktop, mobile phone, desktop etc.
Special or specific purpose computers are computers that are designed to suit just an aim. The architecture of this computers is designed for a particular purpose or task. An embedded system in cars today to detect faults or auto drive functionality in cars or auto pilots are typical examples of specific purpose computers. More examples include DVD players, CD players, desk phones etc.
Type: There are three types of computers
- Digital computers
- Analogue computers
- Hybrid computers
Digital computers are computers that run based on binary codes i.e zeroes and ones. This type of computers are the most common and widely used computers today. They have memory spaces and can store data for future use. Desktops, laptops, mobile forms, calculators, digital watches are examples of digital computers
Analogue computers are computers that accept data in form of physical quantities such as temperature, voltage, pressure etc. such computers are not widely used due to the high use of digital computes and evolution in science and technology. A whining watch or wall clock is an example of analogue computer. Others include mercury thermometers, speedometers. Other complex analogue computers are used for scientific, engineering, military or nuclear operations.
Hybrid computers: This computers combine the architecture of both analogue and digital computers to perform task. The modern gasoline pump used in filling stations today is an example of hybrid computers. Ultra scanners,
Age of technology
- First generation computers
- Second generation computers
- Third generation computers
- Fourth generation computers
First Generation Computers:- These computers were earliest and came about at around 1940s – 1950s they occupied much space due to their large sizes, produced a lot of heat and took much time to complete a task. They used Vacuum tubes for processing.
Second Generation computers:- These computers came about as a result of advancement of the first generation. They worked on better technology and thus produced results faster and had a reduced size compared to first generation. These computers worked by means of transistors.
Third generation computers:- These computers came about in the 1960s – 1970s as an improvement of second generation. They used integrated circuits as a result were faster.
Fourth Generation:-
COMPONENTS OF A COMPUTER
The computer is made up of different parts called components that work together without which the computer itself is not complete and can barely perform any task. There are three components of the computer. There are different classes of computer, but for the purpose of this practical guide much attention is placed on general purpose computers with much reference and emphasis on desktop, and laptop computers. Other class may or will be mentioned for clearer understanding. The components listed below are based on desktop on laptop computers
- User or Human component
- Hard ware component
- Software component
User or Human Component: The components of the computer work together and must be present before any meaningful work can be done.; therefore a person who gives instruction to the computer is also part of the computer as there can be input and thus no processing or output. The human component is the human being using the computer.
Hardware Component: This refers to the physical part of the computer which is visible and can be touched. This component is the whole embodiment upon which all operations are carried out by a user. This includes the monitor, keyboard, and mouse. The hardware is further divided into the following
Input devices: Input devices are hardware components used to send in data (request or commands) to the computer. This component is very important as the computer can only work on sent or given data. The mouse, keyboard are typical examples of input devices. A power button, the numeric key pad on gasoline pump and play, stop on media players are also examples of input devices built into such computers as in case on a laptop computer or mobile phone.
Output devices: The result of processed data is rendered of given to the user as information or output through output devices. Thus we can say output devices are devices used to acquire processed data (information). The printer, monitor and speaker are common examples of output devices. Others include plotters, projector. Other computers used an output medium that is recognized only with such computers especially dealing with specific purpose computers. The output of a processed data in gasoline pump is the outpouring of gasoline through a control pipe, thus the pipe is an output device in case of gasoline pump.
The computer Keyboard: This an input device that contains different kinds of keys or buttons with labels representing their names which distinguishes them in functions. The keyboard is the basic input device without which the computer is almost not of proper use. The key board contain different keys and groups which classify them by similar functions.
Classification of keys on the keyboard
1. Function keys: These keys are labeled F1 – F12 and found at the top of the keyboard. The function keys are not assigned a specific function, their functions varies amongst programs. They are sometimes used in combination of other keys to execute a functions in Windows OS. ALT+F1 is used to close an active window. F1 is used to access help in windows and office programs.
2. Control keys: This set of keys are placed mostly by the sides of the keyboard. They include CTRL, SHIFT, ESC, ALT, CAPS LOCK. Some are independently used while others must be combined with others
3. Alphanumeric keys: These keys takes the second row just below the function keys. They are a combination of alphabets and numbers. The first row contains numbers and a few commonly used symbols, the preceding rows contains alphabets which are not arranged serially in ABC format.
4. Numeric keypad: This keys provides a quick access to numbers other than the alphanumeric keys and arithmetic operators (+, -, /, =). The Numeric keypad looks like a calculator is found by the left end of a keyboard. Not all keyboards supports numeric keypad. The numeric keys work only if the NUM+LOCK is active.
5. Arrow keys: This sets of keys are used to move the cursor around a typing area which can cause the moving up or down a document. They a labeled with arrows facing to the direction of their action and found just beside the numeric keypad.
6. Navigation keys: These keys are used to move about a document or webpage. They include HOME, PAGE UP, PAGE DOWN END etc
7. The Enter Key: This key is used to launch or make an execution of a command; it is also used to create or jump to a new line in a typing area.
8. Space bar: This the longest ket found at the bottom of the keyboard used in creating spaces among characters in a typing area. Some media players use this key to execute play or pause.
9. Back space: It is used to erase or correct misspelt or typing errors
10. Windows Home or start key: It is used to view windows applications and installed softwares; it also provides local search bar to search for documents and files on the computer.
11. DEL: Used to delete or erase selected text or files.
Mouse: The mouse is an input device for freehand operations. Unlike the keyboard the mouse controls the computer by use of a cursor. The mouse looks like a typical house mice and thus its name. It has two buttons and a scroll wheel used to scroll up or down a document or web page. The two buttons primary and secondary left and right buttons respectively. The primary is used to make selections and execute an immediate action while the secondary is used to access multiple actions about a selected file after which the action is executed by clicking the left button.
Monitor: A monitor a device used to display information. It is a TV like device with a screen and otherwise called the VDU (Visual Display Unit). There are two types of monitor Monochrome and color monitors. The first sets of monitors could not display multiple color results as technology had not yet advanced and so all results were display in black and white (grayscale mode). Theses monitors were not advanced and rendered very low quality display and are called monochrome monitors. Color monitors are an advancement of monochrome monitors, they are able to display colored information with better resolution (quality) and run faster. As technology evolved monitors that look exactly like TV diminished and a variety of new monitors with higher speed and quality. Monitors were built previously on CRT (Cathode Ray Tube) technology and now advanced to LCD (Liquid Crystal Display).
Printer: A printer a device that works gives the computer the ability and architecture to bring out in physical form (that can be touched) a typed document or image. Without this device all files remain in the storage of the computer. There two types of monitors color and monochrome monitors. Color monitors are design to print multiple color documents or images while monochrome can print on black and white. Both printers are commonly used today.
Game Pad and Joy stick: These are input devices for playing games.
Scanners: These devices are used to send data into the computer inform document or picture. The data is acquire by passing a ray on the parent or physical document a copy of it is sent to the computer which can be store, printed or any other action performed on it.
Speaker: Speakers are devices that are used to produces, the computer use speakers to output soun information like in movies and music.
Microphone: A microphone is used to take in or send sound data to the computer. Some microphones are built into the computer while other are externally connected to the computer.
Other devices are neither input nor output but are hardware component are important in the running of a computer. They included
System unit: The system unit is the box that houses the motherboard upon which all other components are attached. In lay language most people refer to the system unit as the CPU.
Mother board: The computer being an electronic device runs on electricity and thus an electric board. The board provides features that allow other devices to be attached and therefore complete the functionality of the computer. The monitor, keyboard, CPU, etc are all connected to the motherboard.
Storage devices: Storage devices are devices used to save or store data that for feature use. The computer has the ability to use an internal or external storage device depending on the convenience of the user. The Hard disk drive is the most common and widely used storage device; others include flash drive, CD-ROM, DVD, SanDisk.
CPU: This is the brain of the computer where all process takes place. The speed of a CPU is measured in Mega Hertz (MHz) or Giga hertz (GHz) and basically determines the speed of a computer.
Memory devices: Most times memory is misunderstood for storage. The computer uses memory to execute process and storage to store data for future use. When a request is made the process such request by the use of memory. There are two types of memory; the RAM and ROM short for Random Access Memory and Read Only Memory respectively.
RAM is the computer’s main memory, which it uses to process information. Whenever you work with a file on your computer, you’re using RAM. And the data in that file is temporarily stored in RAM. However, RAM is volatile, which means that the data is stored only as long at the computer has power. Once you shut off your computer, the data is gone. However, you can and should save your data (read: your file). That’s where storage comes in, but more on that later. For now, think of RAM like a notebook: You can read from it and write to it.
ROM (read-only memory) ROM is the computer’s low-level memory, which it uses to perform its most basic functions. This memory is permanent; the data remains even if you shut off the computer. This only makes sense because ROM is required to restart your computer. You never hear people discuss how much ROM you have because the manufacturer usually installs it, and you never touch it. It does all the behind-the-scenes work and then disappears once you’re underway, much like a party planner. You can also think of ROM like a novel: You can read from it, but you can’t write to it (and thus, its name).
Software: This component of the computer is that which is embedded in the computer hardware (storage and memory) that can only be accessed by the use of the hardwares. This software could be refered to as stored instructions, commands that help the computer to process data. There are two types of software; system software and application software.
System software: This type of software is responsible for managing the total hardware of the computer, it provides a platform for other soft wares to run. Operating system, BIOS are typical examples of System software.
Operating System: Operating System otherwise called OS is an example of system software and is responsible for controlling the hardware of a computer and has the ability to install and run other software An operating system is a software program that loads automatically and controls just about everything on your computer. There are a number of operating system including MS-DOS and Microsoft Windows
OS controls the different devices of your computer system. It’s what makes your printer print, what makes graphics and text appear on your monitor, and what makes your mouse point and click.
An operating system is what runs all your programs. Without an operating system, your word processor, Web browser (Internet), and games wouldn’t work. An operating system lets your programs talk to your hardware, so, for example, your word processor can print things to the printer.
An operating system stores information in files and folders on your computer’s local disk, just like you store files and folders in a filing cabinet. An operating system is like an orchestra conductor who makes sure all the parts of your computer—your hardware and programs—work together. Operating systems have been around for a long time—here’s a brief history of the various operating systems out there:
The most commonly used Operating systems are Windows, MAC Linux
Windows OS: The Microsoft Windows OS is widely used and one of the most common Operating systems around. Windows has a variety of versions which differs and most times the newest upgraded with new features which often have high processing speed compared to its parent version. Windows 95, 98, 2000, 2003 are earlier versions of Windows. Newer versions include Windows 7, 8, 10 and as of this date Windows 11 as the latest. Windows is owned and designed by Microsoft Corporations.
Features of Windows
Working with windows
Booting
Log on screen/sign in
Desktop
Features of desktop
Icons
Shortcuts
Files
Desktop background
Folders
Task bar
Date
Network
Volume
Notifications
Start
Working with files
Deleting a file
Creating a file
Copying a file
Moving a file
Renaming a file
File types
BIOS: BIOS stands for Basic Input and Output System, it is stored on the ROM of a computer and provides the basic instruction for a computer system such as OS selection, booting, onboard settings
Application software: An application software helps you accomplish a certain task, such as writing a letter, browsing the Internet, or playing a game. Examples include word-processing programs, spreadsheets, databases, and games. They are designed to run on the operating system for a specific purpose. the provide solutions to human problems.
Functionality of the computer
Speed: The speed of a computer system refers to how much time it takes to run a process. Earlier computers took a long time to process request while modern computers are designed to run faster. The speed of a computer is measured in megahertz as of earlier times but now in gigahertz. This measure refers to the number of revolution per second the computer. And this is a measure of the CPU. Most notebook PCs run on 1.0, 2.0 GHz others run faster at around 3.0, 3.5, 4.0. The RAM of a computer also contributes to the speed of a computer, the lower the RAM the lower the speed. An average notebook PC uses 1GB or 2GB RAM. For a better experience users can go for higher memory space. The Hard Disk Drive also contribute to the speed of a computer, some HDD are optimized and spin faster therefore speed up the computer. It also adviced to alsways have free space on the HDD for a better experience.
Power supply: functionality of a computer largely depends on electricity without which it may be impossible to use. Modern computers are designed to consume less power and can run even on battery; thus the use of UPS (Uninterupted Power Supply) could be adapted to ensure power fluctuation.
INTERNET AND NETWORK
The internet is a term used to represent international network. It is a community or network of global computers to share information. The Internet is the largest network in the world, consisting of millions of computers, all over the world, all connected together.
The Internet was born in the 1960’s when the United States military worried that a nuclear bomb could destroy its computer systems (there weren’t many of them back then). So it placed several computers far apart from each other and connected them with some super-fast telephone lines so that the computers could talk to each other. If a nuclear bomb blew up one computer, another computer could instantly take over; thus, the computer network wouldn’t go down. Years passed and other organizations, such as colleges and universities, started connecting their computers to this growing network to share information. Although the Internet has been around a long time, it wasn’t until the 1990’s that someone thought of a wonderful idea called the World Wide Web. The World Wide Web is what you probably think of when you think of the Internet, although it’s really just a part of the Internet. The Web consists of millions of documents that are stored on hundreds of thousands of computers that are always connected to the Internet. These documents are called Web pages, and you can find Web pages on every subject imaginable—from your local newspaper to online catalogs to airline schedules, and much, much more. Web pages are stored on Web servers. A Web server is a computer, not unlike your own computer, only bigger and faster. There are hundreds of thousands of Web servers located all over the world. Web servers are always connected to the Internet so that people can view their Web pages 24 hours a day.
Network: This a connection or link up of devices to share resources and related devices.
Internet
Web Browser: A Web browser is a program that lets your computer view and navigate the World Wide Web.
Server: A sever is a type of computer that could be said to be super computers. They have high processing speed and can handles millions of requests from different users at a time. This computers are used to host networks and client computers are then connected to it. Websites are hosted on servers. These computers are expensive to maintain and require constant power supply so they can serve content to its host community.
Web page: This is a document displayed on a website on the internet. Web files are displayed in web pages designed by web developers.
Website: The collection of different inter related web pages making up a website.
Email: This an electronic method of sending files. Prior to technology, letters were sent by means of post office; by the evolution of technology letters are being sent through email. An email consist of a mail server which is like a post office; its responsile for mail delivery; a username which is unique like a house address that points only to a particular house. One can’t send or receive mails unless he has an email address. Mails only be sent to registered mail addresses.
Social network: People cluster in markets, under trees, road side to talk, play and interact with other people. The internet has is a global community and has provided places such as listed above where people can chat, interact and catch fun. This community of people is what is referred to as social network. A network with the primary purpose of interaction.
Programs
MS word
How to open MS word
How to create a new file
How to open a previous file
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