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INFORMATION COMMUNICATION TECHNOLOGY
Definition: ICT (information and communications technology - or technologies) is a term that includes any communication device or application, encompassing: radio, television, cellular phones, computer and network hardware and software, satellite systems and so on, as well as the various services and applications associated with them, such as videoconferencing and distance learning. ICTs are often spoken of in a particular context, such as ICTs in education, health care, or libraries. Or ICT stands for Information and Communication Technology and are defined as a set of technological tools and resources used to communicate, create, disseminate, store and manage information. These tools include computers, the internet, broadcasting (radio and Television) The importance of ICTs lies less in the technology itself than in its ability to create greater access to information and communication in undeserved populations. Many countries around the world have established organizations for the promotion of ICTs, because it is feared that unless less technologically advanced areas have a chance to catch up, the increasing technological advances in developed nations will only serve to exacerbate the already-existing economic gap between technological "have" and "have not" areas. Internationally, the United Nations actively promotes ICTs for Development (ICT4D) as a means of bridging the digital divide. Digital divide is a term that refers to the gap between demographics and regions that have access to modern information and communications technology, and those that don't or have restricted access. This technology can include the telephone, television, personal computers and the Internet.
INTRODUCTION TO COMPUTERS What is a computer? A computer is a general-purpose electronic machine that receives / accepts, processes, stores and output data into meaningful information A computer can also be defined as an electronic device operating under control of instructions stored in its own memory that can accept data, manipulate the data according to specified rules, produce results, and store the results for future use.
Characteristics of Computers. Speed : The computers process data at an extremely fast rate, at millions or billions of instructions per second. A computer can perform a huge task in a few seconds that otherwise a normal human being may take days or even years to complete. The speed of a computer is calculated in MHz (Megahertz), that is, one million instructions per second. Accuracy : Besides the efficiency, the computers are also very accurate. The level of accuracy depends on the instructions and the type of machines being used. A computer in other wards does not make any mistakes. For example a computer can accurately give the result of division of any two numbers up to 10 or more decimal places Diligence : Computer, being a machine, does not suffer from the human traits of tiredness and lack of concentration. If four million calculations have to be performed, then the computer will perform the last, four-millionth calculation with the same accuracy and speed as the first calculation. Reliability : Generally, reliability is the measurement of the performance of a computer, which is measured against some predetermined standard for operation without any failure. Storage Capability : Computers can store large amounts of data and can recall the required information almost instantaneously i.e. data can be retrieved whenever required. Versatility : Computers are quite versatile in nature. It can perform multiple tasks simultaneously with equal ease. For example, at one moment it can be used to draft a letter, another moment it can be used to play music and in between, one can print a document as well. Resource Sharing : In the initial stages of development, computers used to be isolated machines. With the tremendous growth in computer technologies, computers today have the capability to connect with each other. This has made the sharing of costly resources like printers possible. Apart from device sharing, data and information can also be shared among groups of computers, thus creating a large information and knowledge base.
Parts of a computer system A complete computer system comprises of four distinct parts. Hardware Software Data
0 (off, No) OR 1 (on, Yes). Byte The Smallest unit of data Storage. A byte is 8 bits, about one character of data. Half a byte is a nibble. Bits and bytes One bit is a single 0 or 1. One byte consists of 8 bits. One kilobyte consists of 1,024 bytes approximately 1000 bytes. One megabyte is 1,024 kilobytes or approximately 1 million bytes. One gigabyte is 1,024 megabytes or approximately 1 billion bytes One terabyte is 1,024 gigabytes or approximately 1 trillion bytes.
WORLD OF ICT ICT is the tools and techniques used to capture, store, manipulate, communicate and use information. Fully exploiting the capability of ICT is of critical importance to the delivery of modern government and businesses in a knowledge - driven economy Use of ICTs in; Education Education is the process of acquiring knowledge and skills, in the traditional model, people learn from others such as parents, teachers and employers. Many forms of printed materials such as books and manuals are used in learning. Today educators also are turning to ICT to assist with education. As the cost of computers and other ICT tools drops, many schools and companies can afford to equip labs and class rooms with computers. E- Learning Sometimes the delivery of education occurs at a place while the learning occurs at other locations (distance learning). e.g. Students can take classes on web. More than 70% of colleges in developed countries offer some type of distance learning classes. A few even offer entire degrees online. Students use software to assist with learning or complete assignment. Through ICT there has been enhanced class room teaching through use of presentations as well as projectors to deliver the information in a more convincing way.
Schools and Institutions use computers to typeset examinations. Online registration and admissions: Most institutes and schools have opened up websites which offer online registration and admissions without visiting the institute physically. Ubiquitous learning (through virtual mentors / teacher) Research. Teachers and students use the internet to carry out research on various topics. Communication (Teacher-students / Teachers - parents communication) through e-mail. Online discussion (video-conferencing).
E- Commerce. E - Commerce is the general term used for companies trading online. It is a shorter way of saying electronic trading. The “E” is for Electronic and commerce means trading. The prevailing E-commerce activities have been divided into 3 major categories Business-to-Consumer (B2C) In a Business-to-Consumer E-commerce environment, companies sell their online goods to consumers who are the end users of their products or services. Usually, B2C E-commerce web shops have an open access for any visitor, meaning that there is no need for a person to login in order to make any product related inquiry.
1. Business-to-Business (B2B) In a Business-to-Business E-commerce environment, companies sell their online goods to other companies without being engaged in sales to consumers. In most B2B E-commerce environments entering the web shop will require a log in. B2B web shop usually contains customer-specific pricing, customer-specific assortments and customer-specific discounts. 2. Consumer-to-Business (C2B) In a Consumer-to-Business E-commerce environment, consumers usually post their products or services online on which companies can post their bids. A consumer reviews the bids and selects the company that meets his price expectations. 3. Consumer-to-Consumer (C2C) In a Consumer-to-Consumer E-commerce environment consumers sell their online goods to other consumers. A well- known example is eBay.
Art, leisure and entertainment One of the most compelling ways in which technology has affected our lives is in the way we are entertained or we choose to entertain ourselves The internet can be used to book tickets for concert or visit to the cinema. Portable devices like phones are used for playback music and video files. Digital transmission is used to broadcast TV and radio programs. TV programs are provided free to air or on a pay to view basis through satellite and cable services. Music download from the internet, the internet is used as a channel for the distribution of music through music download website. Playing of games is an important leisure activity for many computer users.
Industrial, technical and scientific uses Many processes that were traditionally performed manually in the manufacturing industry are now done using a variety of technologies. Industries that manufacture products usually have large number of employees and high capital expenditure capital includes factories ware houses, machinery and computers.
1. CAD (Computer Aided Design) Computers are used to design the model of a product on the computer. This process is called Computer Aided Design 2. CAM (Computer Aided Manufacturing) Computer Aided Manufacturing (CAM) refers to the use of computers to assist with manufacturing process as fabrication and assembly. Often robots carryout processes in a CAM environment, 3. Process control Some entire manufacturing processes are now fully automated and controlled by computer technology. One of the best known examples is the car manufacturing process, where robots build and process most of the infrastructure re with minimal human input. Some companies have automated packaging processes that use computer - operated packing machines capable of packing a wide range of products, including perishable and easily damaged products like fruits or vegetables.
Uses of computers at Home Computers help in calculating home grocery bills. Computers can be used as Television sets those that have TV cards. Computers can act as radios at home since music can be heard from computers by either inserting in a CD or MP3. You can access internet on a computer at home
Implications of using icts Social / ethical Positive implication ICT has enabled efficient and instant communication through the use of TV, radios and telephones with comprehensive news. Elders were custodians of secrecy and indigenous knowledge, technology has demanded that their Knowledge be drained and stored in DB (Database) where much of it is moved to the public Domain Fast and easy way of getting friends through social networks like Face book, twitter e.t.c Use of mobile money to pay bills, fees, and convey money to our family members without incurring costs E-policy, viewing policies online. Online Education where by people gets academic qualifications online. People can communicate any time and at any place with the introduction of phones Information rich and easy access through the internet
Negative implications. Social Networking has removed the boundaries of respect and direct dialogue between and among youths and elders. Access of pornographic material and immoral movies by young people through the internet has led to moral decay. Culture degeneration due the exposure of western culture. ICT has diluted traditional community religions. Information poor: not all people have access to computers thus making it difficult to access information that can be got from computers. High level of unemployment as a result of introduction of ICTs in most companies. ICT replace
Green computing This is the environmentally responsible use of computers and related resources. It can also be defined as the practice of efficiently and effectively using computers and related resources with minimal or no impact on the environment Advantages Reduced energy usage from green computing helps lower carbon dioxide emissions that come from the fuel used in power plants and transportation. Conserving resources means less energy is required to produce, use and dispose of products which are environmental friendly. Saving energy and resources means saving money. Reduce the risk existing in the laptop such as chemical known to cause cancer, nerve damage and immune reactions in human. Green computing also includes changing government policy to encourage recycling and lowering energy use by individuals and business. Disadvantage High start-up cost Not readily available Still experimental
Green computing suggestions Use computers and devices that comply with the ENERGY STAR program. Do not leave the computer running overnight. Turn off the monitor, printer, and other devices when not in use. Use paperless methods to communicate. Recycle paper. Buy recycled paper. Recycle toner cartridges. Recycle old computers and printers. Telecommute (saves gas).
Starting a computer Turn on the power button on the system Unit then turn on the power button of the monitor or visual display unit. Booting This is the process by which the computer loads system files into the main memory. This process involves carrying out diagnostics test. Or is the process of starting or restarting a computer. Types of booting
- Cold booting. This is the starting up of the computer which has not been on by turning on power buttons.
- Warm booting This is the restarting of the computer. It is known as system reset which can be done by processing the resetting button.
Files and folders A file is collection related information that is given a name and stored so that it can be retrieved when needed. File names can contain two characters including spaces. A folder is a collection of files. A folder can also contain many sub-folders Creating a folder From the main option select new and then click folder. Type in the name of the new folder. Or Right click on the desktop From the sub menu choose New then click on folder By default a new folder will be created with a tittle new folder Type the name of the new folder and press ENTER. Renaming a folder After selecting the folder Select rename from the file option Or click the right button and select rename. Or Press F2 from the keyboard Deleting a folder Files deleted are put in the recycle bin. A recycle bin is a place for files no longer needed. To delete a file do one of the following. Select or (click on the file).
Hardware that is not part of the system unit is sometimes called a peripheral device or device.
INPUT DEVICES An input device is any hardware component that allows you to enter data or instructions into the computer Six widely used input devices are the keyboard, mouse, microphone, scanner, digital camera and PC video camera.
Mouse. Is a pointing device used to manipulate on screen objects. A mouse is a small hand held device used for pointing. A mouse moves a pointer on the computer screen. It acts like a finger, allowing you to press buttons and select objects Using your mouse Basic parts A mouse typically has two buttons: a primary button (usually the left button) and a secondary button (usually the right button). The primary button is the one you will use most often. Most mice also include a scroll wheel between the buttons to help you scroll through documents and web pages more easily. On some mice, the scroll wheel can be pressed to act as a third button. Advanced mice might have additional buttons that can perform other functions.
Left Hand Button - Use to point and select Right Hand Button - To open menus, commands Using the scroll wheel If your mouse has a scroll wheel, you can use it to scroll through documents and web pages. To scroll down, roll the wheel backward (toward you). To scroll up, roll the wheel forward (away from you). Cord - plugs mouse into computer Mouse operations Pointing Pointing to an item on the screen means moving your mouse so the pointer appears to be touching the item. When you point to something, a small box often appears that describes the item. Clicking (single-clicking). To click an item, point to the item on the screen, and then press and release the primary button (usually the left button). Clicking is most often used to select (mark) an item or open a menu. This is sometimes called single-clicking or leftclicking.Right click to open a menu and to give more advanced instructions Double-clicking. To double-click an item, point to the item on the screen, and then click twice quickly. If the two clicks are spaced too far apart, they might be interpreted as two individual clicks rather than as one double-click.Double-clicking is most often used to open items on your desktop. For example, you can start a program or open a folder by double-clicking its icon on the desktop. Drag. You can move items around your screen by dragging them. To drag an object, point to the object on the screen, press and hold the primary button, move the object to a new location, and then release the primary button.Dragging (sometimes called dragging and dropping) is most often used to move files and folders to a different location and to move windows and icons around on your screen.
Tips for using your mouse safely. Holding and moving your mouse properly can help you avoid soreness or injury to your wrists, hands, and arms, particularly if you use your computer for long periods of time. Here are some tips to help you avoid problems: Place your mouse at elbow level. Your upper arms should fall relaxed at your sides. Don't squeeze or grip your mouse tightly. Hold it lightly. Move the mouse by pivoting your arm at your elbow. Avoid bending your wrist up, down, or to the sides. Use a light touch when clicking a mouse button.
- Back space key. It is used to erase / rub characters to the left side of the cursor.
- Space bar. It is the longest key on the keyboard and it is used to insert spaces between word and characters.
- Caps lock. It is used to turn capital letters into small letters and small letters into capital letters. When the caps lock is pressed a caps lock light on the top right corner is turned on to indicate that you are in capital letters to switch to small letters press the caps lock button again,
- Shift key. It is used to activate characters on top of the buttons, it can also turn in either small letters or capital letters dependin g on the keyboard case mode.
- Delete key. It is used to erase characters on the right side of the cursor.
- Fl: It is used as help.
- Esc (escape) : it is used to cancel an application under taken.
Functions of the keyboard. Its keys allow the user to type data in form of text. It can be used to command the computer to perform an operation or task, It is the major connector between the user and the computer, Without it die user may not be put in the language the compute understands,
Other input devices Scanner. This is a light-sensing input device that reads printed text and graphics and translates the results into a form a computer can process Digital camera. It allows users to take pictures and store the photographed images digitally Instead of on traditional film. Web cam. This is a video camera that displays it's output on a web page. Joysticks. It is a pointing device with vertical lever for playing games. Touch Screen. A touch screen is a special kind of input device that allows the direct selection of a menu item or the desired icon with the touch of finger. Essentially, it registers the input when a finger or other object is touched to the screen Bar code reader. Bar code is a machine-readable code in the form of a pattern of parallel vertical lines of varying widths. It is commonly used for labeling goods that are available in super markets and numbering
books in libraries. This code is sensed and read by a bar code reader using reflective light. The information recorded in bar code reader is then fed into the computer, which recognizes the information from the thickness and spacing of bars.
OUTPUT DEVICES This is any type of hardware component that conveys information one or more people. Commonly used output devices include display devices, printers, speakers and headsets, fax machines and fax modems, multifunction peripheral data projectors e.t.c. Output is data that has been processed into useful form. The computer processes input (data) into information (Output). The out put, which can be easily understood and used by human beings, are of the following two forms:
- Hard Copy: The physical form of output is known as hard copy. In general, it refers to the recorded information copied from a computer onto paper. Hard copy output is permanent and a relatively stable form of output. This type of output is also highly portable. Paper is one of the most widely used hard copy output media.
- Soft Copy: The electronic version of an output, which usually resides in computer memory and/or on disk, is known as soft copy. Unlike hard copy, soft copy is not a permanent form of output. It is transient (lasting for a short period of time) and is usually displayed on the screen. This kind of output is not tangible, that is, it cannot be touched. Soft copy output includes audio and visual form of output, which is generated using a computer
Following are few of the important output devices, which are used in Computer Systems: Monitors Monitor commonly called as Visual Display Unit (VDU) is the main output device of a computer. It forms images from tiny dots, called pixels,that are arranged in a rectangular form. The sharpness of the image depends upon the number of the pixels. There are two kinds of viewing screen used for monitors: Cathode-Ray Tube (CRT). In the CRT, display is made up of small picture elements called pixels for short. The smaller the pixels, the better the image clarity or resolution. It takes more than one illuminated pixel to form whole character, such as the letter 'e' in the word help. Flat-Panel Display Monitor The flat-panel display refers to a class of video devices that have
information / data. Hard copies last longer if stored in a safe place compared to softcopy, which must be all the time changed with the technological developments taking place.
Speakers and headsets An audio output device is a component of a computer that | produces music, speech, or other sounds such as beeps. Two commonly used audio output devices are speakers and headsets. Many personal computers users add stereo speakers to their computers to generate a high-quality sound. Fax machines and Fax Modems A fax machine is a device that transmits and receives documents over telephone lines. A fax modem is a modem that allows you to send (and sometime receive) electronic documents as faxes
Data projectors These are devices that take the images from a computer screen and projects it onto a larger screen and projects it onto a larger screen so an audience of people can see the image clearly. Qn1: Mention devices which can be classified as both input and also output computer hardware.
- Touch Screen - a touch-sensitive display device you touch words, pictures, numbers, letters, or locations identified on the screen.
- a floppy diskette drive - a device used for both reading and writing data to and from a floppy disk
- Optical Disk Writer - a device used for both reading and writing data to and from optical disks such as CDs, DVDs and Blu-ray disks
- a hard disk drive - a device used for both reading and writing data to and from a Hard disk
- USB flash drive - used for both reading and writing data to and from Flash disks 6. Modem
STORAGE
Storage holds data, instruction and information for future use e.g. computers can store lots and millions of customers' names and addresses. A computer keeps data, instructions and information on storage media e.g. floppy diskette, zip disk, USB flash disk, Hard disk, memory cards and Tapes.
Storage devices These records (writes and records item) information to and from a storage media. Storage medium: also called secondary storage, is a physical material on which a computer keeps data, instructions, and information. E.g. floppy disk, Zip disk, hard disks, CDs and DVDs, tapes, PC Cards. Storage Capacity is the number of bytes (Characters) a storage medium can hold. Reading: is the process of transferring data, instructions and information from a storage medium into the memory. Writing: is the process of transferring items from memory to a storage medium. The speed of a storage media is defined by its access time, which is the amount of time it takes to locate an item on a storage medium.
Primary Memory (Main Memory) Primary memory holds only those data and instructions on which computer is currently working. It has limited capacity and data gets lost when power is switched off. It is generally made up of semiconductor device. These memories are not as fast as registers. The data and instructions required to be processed earlier reside in main memory. It is divided into two subcategories RAM and ROM. Characteristic of Main Memory These are semiconductor memories. It is known as main memory. Usually volatile memory. Data is lost in case power is switched off. It is working memory of the computer. Faster than secondary memories. A computer cannot run without primary memory. A RAM constitutes the internal memory of the CPU for storing data, program and program result. It is read/write memory. It is called random access memory (RAM). RAM is volatile, i.e., data stored in it is lost when we switch off the computer or if
