Computer Fundamentals for Standard VII and VIII
Students are requested to copy the notes which are there in the book and ignore the rest, in their notebooks in their free time. The first page is common for Standard VII and VIII and the Second and Third Page will be different depending on the school and standard. The second page will be HTML and the third page will be GWBasic.
Computer
A computer is an electronic data processing device, which accepts and stores data input, processes the data input, and generates the output in a required format.
Step 1 - Takes data as input.
Step 2 - Stores the data/instructions in its memory and uses them as required.
Step 3 - Processes the data and converts it into useful information.
Step 4 - Generates the output.
Step 5 - Controls all the above four steps.
Advantages of Computers
High Speed
The computer is a very fast device.
It is capable of performing calculations of a very large amount of data.
The computer has units of speed in microseconds, nanoseconds, and even the picosecond.
It can perform millions of calculations in a few seconds as compared to a man who will spend many months performing the same task.
Accuracy
In addition to being very fast, computers are very accurate.
The calculations are 100% error-free.
Computers perform all jobs with 100% accuracy provided that the input is correct.
Storage Capability
Memory is a very important characteristic of computers.
A computer has much more storage capacity than human beings.
It can store large amount of data.
It can store any type of data such as images, videos, text, audio, etc.
Diligence
Unlike human beings, a computer is free from monotony, tiredness, and lack of concentration.
It can work continuously without any error and boredom.
It can perform repetitive tasks with the same speed and accuracy.
Versatility
A computer is a very versatile machine.
A computer is very flexible in performing the jobs to be done.
This machine can be used to solve problems related to various fields.
At one instance, it may be solving a complex scientific problem and the very next moment it may be playing a card game.
Reliability
A computer is a reliable machine.
Modern electronic components have long lives.
Computers are designed to make maintenance easy.
Automation
Computer is an automatic machine.
Automation is the ability to perform a given task automatically. Once the computer receives a program i.e., the program is stored in the computer memory, then the program and instruction can control the program execution without human interaction.
Reduction in Paper Work and Cost
The use of computers for data processing in an organization leads to a reduction in paperwork and results in speeding up the process.
As data in electronic files can be retrieved as and when required, the problem of maintenance of a large number of paper files gets reduced.
Though the initial investment for installing a computer is high, it substantially reduces the cost of each of its transactions.
Disadvantages of Computers
No I.Q.
A computer is a machine that has no intelligence to perform any task.
Each instruction has to be given to the computer.
A computer cannot take any decision on its own.
Dependency
It functions as per the user’s instruction, thus it is fully dependent on humans.
Environment
The operating environment of the computer should be dust free and suitable.
No Feeling
Computers have no feelings or emotions.
It cannot make judgment based on feeling, taste, experience, and knowledge unlike humans.
Application of computers
· Business
· Banking
· Insurance
· Education
· Marketing
· Healthcare
· Engineering Design
· Military
· Communication
· Government
Computer has now become an integral part of corporate life. Business transactions take place very easily, accurately and records of all the business transactions can be stored.
Today computers can be found in every store, supermarket, restaurant, office, etc.
Almost every bank uses computers to keep records of money transactions and financial documents. It is also used in this sector because of the speed, convenience, and security that it provides.
ATM machines which are completely automated are making it even easier for customers to deal with banks.
Application of computers - Insurance
Insurance claims examiners rely on computers to review insurance claims, doctor's reports, investigative notes and actual insurance policies to determine whether the company will pay a claim or deny.
Application of computers - Education
Today computer has become an important part of one’s education because we are using computers in every field. Without the knowledge of computer, we cannot get a job and perform well in it. So computers can improve job prospects. Computers are used in class rooms by teachers to teach, maintain records of students, online learning and assessments, etc.
Application of computers - Marketing
Computers offer away for companies to give surveys without actually going out and meeting customers. One role of information technology in marketing is the gathering survey data on a company's website, using third-party internet services or sending out email questionnaires.
Application of computers – Health Care
Diseases can be easily diagnosed with the help of a computer and we can also know about the cure. Almost every piece of medical diagnostic equipment uses a computer. In the field of healthcare, computers are used to perform various tasks such as reviewing the medical records of patients.
Application of computers – Engineering Design
Many tools are available today that helps engineers/designers achieve their objectives. Computer-Aided Design (CAD) and Computer-Aided Engineering (CAE) are software that allows engineers to be creative while satisfying the technical requirements of a product.
Application of computers - Military
Computers are largely used in defense. Modern tanks, missiles, weapons, etc. Military also employs computerized control systems. Some military areas where a computer has been used are:
1. Missile Control
2. Military Communication
3. Military Operation and Planning
4. Smart Weapons
Application of computers - Communication
Communication has become very easy and simple through the internet and email. The computer communicates using telephone lines, modems, and satellites. Through email, we can send messages in a split-second to anybody in any part of the world. On the other hand, the traditional form of communication, for example, postal services takes many days to reach the recipient.
Application of computers - Government
Computers play an important role in government services. Some major fields in this category are:
1. Budgets
2. Income and Sales tax department
3. Computerization of voters lists
4. Computerization of PAN card
5. Weather forecasting
Application of computers - Media
Almost every type of editing and audio-visual composition can be made by using special software made for the purpose. Some software can even make three-dimensional figures which are mostly used in making cartoon films. Special effects for action and science fiction movies are also created on computers.
Generation of Computers
· First Generation - The period of the first generation: 1946-1959. Vacuum tube based.
· Second Generation - The period of the second generation: 1959-1965. Transistor based.
· Third Generation - The period of the third generation: 1965-1971. Integrated Circuit based.
· Fourth Generation - The period of fourth generation: 1971-1980. VLSI microprocessor based.
· Fifth Generation - The period of fifth generation: 1980-onwards. ULSI microprocessor based.
First Generation Computers
Features of First Generation Computers
Vacuum tube technology
Unreliable and Huge size
Supported machine language only
Very costly
Generated a lot of heat needs Air Conditioners
Slow input and output devices
Examples ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650
Second Generation Computers
Features of Second Generation Computers
Use of transistors in place of vacuum tubes
Faster, Reliable, smaller in size as compared to first generation computers
Generated less heat, Consumed less electricity as compared to first generation computers
Still very costly and AC required
Supported machine and assembly languages
Examples IBM 1620, IBM 7094, CDC 1604, CDC 3600, UNIVAC 1108
Third Generation Computers
Features of Third Generation Computers
Integrated Circuits(IC) used
More reliable in comparison to previous two generations
Smaller size and generated less heat
Faster and lesser maintenance
Costly and AC required
Consumed lesser electricity
Supported high-level language
Examples IBM-360 series, Honeywell-6000 series, PDP (Personal Data Processor), IBM-370/168, TDC-316
Fourth Generation Computers
Features of Fourth Generation Computers
VLSI technology used Very cheap
Portable of its small size and reliable
No AC required
Concept of internet was introduced
Great developments in the fields of networks
Computers became easily available
Examples DEC 1019, STAR 1000, PDP 11, CRAY-1(Super Computer), CRAY-X-MP(Super Computer)
Fifth Generation Computers
Features of Fifth Generation Computers
ULSI technology
Development of true artificial intelligence
Advancement in Superconductor technology
More user-friendly interfaces with multimedia features
Availability of very powerful and compact computers at cheaper rate
Examples Desktop, Laptop, NoteBook, UltraBook, Chrome Book
Types of Computers
There are majorly 4 types of Computers
· Super Computer
· Mainframe
· Workstation
· Microcomputer
The computers which are used to process a huge amount of data at once are called Supercomputers. They are mostly used in scientific and engineering operations where the processing is complex. They are expensive and complicated to work. For example – The computers used by ISRO to launch space shuttles.
Mainframe Computer
Computers designed to be used in large firms and organizations where a lot of people have to work on the same database are called mainframe computers. They are almost equally as expensive as Supercomputers and are the fastest working computers at present. They are mostly used in Banks.
Workstation
Usually, a single-user system is called a workstation. The RAM for such systems is more, and the processors are quite fast. They are mostly used by an individual and can be used for multiple purposes.
Microcomputer
Designed for personal use only. This type of computer can easily be moved from one place to the other. They have a personal storage area, input & output unit, and a Central Processing Unit. Examples of microcomputers are desktop, laptop, mobile phone, tables, etc.
Input Device
An input device is any hardware device that sends data to a computer, allowing you to interact with and control it.
Types of Input Devices
The best examples are:-
Keyboard
Mouse
Joy Stick
Light pen
Graphic Tablet
Touch screen
Voice Recognition
Microphone
Scanner
Magnetic Ink Character Reader(MICR)
Optical Character Reader(OCR)
Bar Code Reader
Webcam
Digital Camera
Keyboard
A keyboard is one of the primary input devices used with a computer. Similar to an electric typewriter, a keyboard is composed of buttons used to create letters, numbers, and symbols, and perform additional functions.
Mouse
A computer mouse is a hand-held pointing device that detects two-dimensional motion relative to a surface. This motion is typically translated into the motion of a pointer on a display, which allows a smooth control of the graphical user interface of a computer.
Joy Stick
A joystick is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer.
Light pen
A light pen is a computer input device in the form of a light-sensitive wand used in combination with a computer's cathode-ray tube (CRT) display. It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy.
Graphic Tablet
A graphics tablet is a computer input device that enables a user to hand-draw images, animations and graphics, with a special pen-like stylus, similar to the way a person draws images with a pencil and paper. The device consists of a rough surface upon which the user may "draw" or trace an image using the attached stylus, a pen-like drawing apparatus.
Touch screen
A touch screen is a display device that allows the user to interact with a computer using their finger or stylus. They're a useful alternative to a mouse or keyboard for navigating a GUI (graphical user interface). Touch screens are used on a variety of devices, such as computer and laptop displays, smartphones, tablets, cash registers, and information kiosks.
Voice Recognition
Voice Recognition is one of the newest, most complex input techniques used to interact with the computer. The user inputs data by speaking into a microphone. The simplest form of voice recognition is a one-word command spoken by one person. Each command is isolated with pauses between the words.
Microphone
The microphone is a computer input device that is used to input the sound. It receives the sound vibrations and converts them into audio signals or sends to a recording medium. The audio signals are converted into digital data and stored in the computer.
Scanner
A scanner is an input device that scans documents such as photographs and pages of text. When a document is scanned, it is converted into a digital format. This creates an electronic version of the document that can be viewed and edited on a computer.
Magnetic Ink Character Reader(MICR)
Magnetic ink character recognition code, known in short as MICR code, is a character-recognition technology used mainly by the banking industry to streamline the processing and clearance of cheques and other documents.
Optical Character Reader(OCR)
Optical character recognition or optical character reader is electronic or mechanical conversion of images of typed, handwritten or printed text into machine-encoded text, whether from a scanned document, a photo of a document, a scene-photo or from subtitle text superimposed on an image.
Bar Code Reader
A barcode reader is an optical scanner that can read printed barcodes, decode the data contained in the barcode and send the data to a computer. Like a flatbed scanner, it consists of a light source, a lens, and a light sensor translating for optical impulses into electrical signals.
WebCam
A webcam is a video camera that feeds or streams an image or video in real-time to or through a computer to a computer network, such as the Internet. Webcams are typically small cameras that sit on a desk, attach to a user's monitor, or are built into the hardware.
Digital Camera
A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film.
Output Devices
An output device is any piece of computer hardware equipment which converts information into human-readable form. It can be text, graphics, audio, and video.
Monitor
A computer monitor is an output device that displays information in pictorial form. A monitor usually comprises the visual display, circuitry, casing, and power supply. It generates a soft copy of the output. Three types of monitors are available CTR, LCD, TFT.
CRT Monitors
A cathode-ray tube is a vacuum tube containing one or more electron guns, the beams of which are manipulated to display images on a Fluorescent screen.
LCD Monitors
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical a device that uses the light-modulating properties of liquid crystals combined with polarizers.
TFT Monitors
A TFT monitor uses thin-film transistor technology in an LCD display. LCD monitors, also called flat panel displays, are replacing the old-style cathode ray tubes (CRTs) in both televisions and computer displays. Nearly all LCD monitors today use TFT technology.
Printers
A printer is an output device that prints paper documents. This includes text documents, images, or a combination of both. The two most common types of printers are inkjet and laser printers. It prints a Hard copy of the Output.
Types of printers are inkjet printers and laser printers.
Inkjet Printers
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper and plastic substrates. Inkjet printers are the most commonly used type of printer, and range from small inexpensive consumer models to expensive professional machines.
Laser Printers
Laser printers are similar to photocopiers. They are mostly used for commercial and office purposes. Instead of using ink, laser printers use toners to transfer data onto the paper. Businesses use these printers because they are reliable, highly efficient and produce high-quality photos.
Plotters
A plotter is a printer designed for printing vector graphics. Instead of printing individual dots on the paper, plotters draw continuous lines. This makes plotters ideal for printing architectural blueprints, engineering designs, and other CAD drawings.
Two types of plotters are drum plotter and flat bed plotter.
Speakers
A computer speaker is an output hardware device that connects to a computer to generate sound. The signal used to produce the sound that comes from a computer speaker is created by the computer's sound card.
Headphones or Earphones
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are an electronic device which converts an electrical signal to a corresponding sound.
Multimedia Projectors
A projector is an output device that takes images generated by a computer or Blu-ray player and reproduce them by projection onto a screen, wall, or another surface.
Memory
Memory is very much like our brain as it is used to store data and instructions. Computer memory is the storage space where data is to be processed, and instructions needed for processing are stored.
Types of Memory
· Primary Memory
· Secondary Memory
Primary Memory
Primary memory is the main memory of the computer system. Accessing data from primary memory is faster because it is an internal memory of the computer. Two types of primary memory are RAM and ROM.
Random Access Memory
Random-access memory which is also known as RAM is generally known as the main memory of the computer system. It is called temporary memory. The information stored in this type of memory is lost when the power supply to the PC or laptop is switched off.
RAM is classified as Static RAM and Dynamic RAM
Read-Only Memory
It stands for Read Only Memory. ROM is a permanent type of memory. Its content is not lost when the power supply is switched off. The computer manufacturer decides the information of ROM, and it is permanently stored at the time of manufacturing which can not be overwritten by the user.
Types of ROM
· PROM – Programmable Read-Only Memory
· EPROM – Erasable Programmable Read-Only Memory
· EEPROM – Electrically Erasable Programmable Read-Only Memory
· EAPROM – Electrically Alterable Programmable Read-Only Memory
Secondary Memory
All secondary storage devices which are capable of storing high volume data is referred to secondary memory. It's slower than primary memory. It can save a substantial amount of data, in the range of gigabytes to terabytes. This memory is also called backup storage or mass storage media.
Mass storage devices
The magnetic disk provides cheap storage and is used for both small and large computer systems.
Two types of magnetic disks are:
Floppy disks
Hard disks
Floppy Disks
A floppy disk or floppy diskette is a type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks are read from and written to by a floppy disk drive.
Hard Disks
A hard disk drive (HDD), hard disk, the hard drive is an electromechanical data storage device that stores and retrieves digital data from the rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces.
Flash memory or Universal Serial Bus(USB)
Flash memory or drive is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. Flash memory or drives are removable, rewritable and are physically very small. The capacity of flash memory or drives is also increasing significantly as today 1TB pen drive is also available in the market.
Optical drives
This secondary storage device is from which data is read and written with the help of lasers.
Examples are
CD
DVD
Blue Ray
Compact Disk
This is storage medium that is usually used to store video, audio, especially music, and information in digital form. A standard compact disc comes with a capacity of about 650-700 MB of data.
Digital Versatile Disk
A DVD is a disc on which a film or music is recorded. DVD discs are similar to compact discs but hold information up to 4.7 GB as compared to 700 MB in the case of Compact Disk. DVD is an abbreviation for 'digital video disk' or 'digital versatile disk'.
Blu-ray Disk
A Blu-ray disk (BD) is a high-capacity optical disk medium developed for recording, rewriting, and playing back high-definition video. It can store large amounts of data up to 25 GB. Blu-ray disks support higher resolutions compared to DVDs.
Software
Software is a collection of instructions that enable the user to interact with a computer, its hardware, or perform tasks. Without software, most computers would be useless. For example, without your Internet browser software, you could not surf the Internet.
Types of Software Languages
There are two broad categories of computer languages.
1. Low-level languages
2. High-level languages
Low-level Languages
These programming languages are designed for particular computer architecture and are therefore, often described as machine-oriented languages.
Low-level languages can be divided into two categories.
1. Machine language
2. Assembly language
Machine language
Machine language is the language in which instructions are given in the form of strings of 0s and Is. Machine language programs are understood by the computer without any translations and hence, are executed very fast as compared to programs written in other languages. Machine language programs are machine-dependent, that is, the program written for one computer may not work on another.
Assembly language
Assembly language is the language in which instructions are given in the form of abbreviated words called mnemonics. For example, the mnemonic LD is used for loading a program, MOV is used for moving data, and ADD is used for adding data. An assembly language program is also machine-dependent. Programs written in assembly language are not directly executable and require a translator known as an assembler.
High-level Languages
A high-level language is a language in which programs are written using English-like words and mathematical symbols. It is very easy for programmers to learn and use high-level languages. It is independent of a machine. It is less error-prone and debugging is easy.
Advantages of high-level languages
1. Understandability: Programs written in these languages are easier to read and understand than those in low-level languages.
2. Debugging: It is very easy to find and remove errors in programs written using high-level languages.
3. Portability: High-level language programs are machine-independent. Programmers do not require details of the underlying hardware to write programs. Programs written for one computer can be executed on any other computer with minor changes or no changes at all.
Classification of Computer Software
Software is a collection of programs that provide instructions to the computer to perform specific tasks. Computer software can be classified into the following categories.
System Software
System software is required to control the operations of a computer system. It helps to manage and run the computer hardware in an efficient manner. It controls all operations like reading data from input devices, transmitting processed information to output devices, checking system components, and converting data/instructions to a form that a computer can understand.
The system software can further be classified into three categories.
1. Operating system
2. Language processor
3. Utility software
Operating System
An operating system serves as an interface between the user and the hardware. It also ensures that the computer hardware is used in an efficient manner. The operating system acts as a resource manager by allocating these resources to specific programs and applications as and when required.
Popular Operating Systems
Some popular operating systems used on desktops and laptops are Microsoft Windows, Linux and Mac OS.
Mobile phone Operating System
Android and iOS are examples of popular operating system used on mobile phones.
Language processor
A computer understands the language of 0’s and 1’s, called the binary or machine language. Writing programs in machine language is very difficult. This led to the development of language translators (Assembler, Compiler, Interpreter). The software program that does this task of translation is called a language processor.
Classification of Language processors
Language processors are divided into three types
1. Assembler
2. Compiler
3. Interpreter
Assembler
An assembler converts a program is written in an assembly language into its equivalent machine language.
Compiler
A compiler converts a program or a source code written in a high-level language into the machine language before execution. It runs through the entire high-level language program in one go and reports all the errors it finds in the source code along with the line numbers. After all the errors are removed, the compiler gives the machine-level equivalent code called the object program or the object code.
Interpreter
An interpreter is a language processor that works by reading and executing the source code of a high-level language program line by line. If there is an error in any line, it reports it at the same time and program execution cannot resume until the error is rectified. The object code produced by the interpreter cannot be saved. So, every time the program is run, it needs to be interpreted again to obtain the object code.
Utility software
Utility software is programs designed to perform maintenance work on a computer system to help in its smooth functioning. Examples of this software are Disk Clean up utility, Antivirus software (such as Norton, AVG, Quick Heal) and Data Compression software (WinZip, WinRAR) and so on.
Application Software
Application software is a set of programs designed to help the user to perform specific tasks. Numerous application software programs have been developed over the years to serve different purposes. We can choose an application software depending upon our requirements.
Application software can be divided into two categories.
• General-purpose application software
• Specific purpose application software
General-purpose application software
General-purpose application software is developed keeping in mind the needs and requirements of general people.
Word processing Software
This software is used for creating documents such as letters, stories and reports. All the types of word processing software provide options for creating, editing, formatting and printing text and graphics in a document. Examples of word processing software are Word, WordPerfect
Spreadsheet Software
This software accepts data values in a row and column format and lets us create, manipulate, calculate and analyze data in the desired manner. Examples of spreadsheet software are Excel, Lotus 1-2-3, and Calc
Database Management System (DBMS)
It is a software program that lets us store large amounts of data in an organized manner. A DBMS can store details about customers, employees, products, students, and so on. It also provides tools for searching data and generating reports based on conditions. Examples of DBMS software are Oracle, Access, Visual FoxPro, and Base
Desktop Publishing Software (DTP)
This type of software is used for designing books, journals, brochures, newspapers, and so on. Examples of desktop publishing software are QuarkXPress and Adobe InDesign.
Graphics, Multimedia and Presentation Software
Graphics software is used to work with images. The software that manipulates images, text, sound, animation, and video is called multimedia software. Presentation software is used to display information in a dynamic manner such as a slideshow.
Specific purpose application software
Specific purpose application software is developed keeping in mind the requirements of an organization or an individual. Software programs that are designed especially to achieve specific tasks are known as customized software.
Examples of Specific purpose Application Software
• Accounting Management Software,
• Reservation system,
• Human Resource Management system,
• Attendance system,
• Payroll system,
• School Inventory and Control system and Billing system.
The Open-Source Initiative (OSI) is an organization dedicated to promote open-source software.
Open-source software is distributed under a licensing arrangement. It allows the source code to be accessible to the users and organizations so that they may study and change it to achieve new levels of quality, growth, and innovation. Open-source software may or may not be available free of cost.
Proprietary software
Proprietary software is computer software on which there are restrictions on use, modification, copying, or redistribution. These restrictions can be imposed by preventing access to the source code or by legal means such as through copyright and patents.
Examples of popular open-source software
Ubuntu
Ubuntu is a Linux-based operating system. It is designed for computers, smartphones, and network servers. The system is developed by a UK-based company called Canonical Ltd. All the principles used to develop the Ubuntu software are based on the principles of Open Source software development.
Android
Android is a mobile operating system based on a modified version of the Linux kernel and other open source software, designed primarily for touchscreen mobile devices such as smartphones and tablets.
OpenOffice
Office Suite that includes a word processor (Writer), a spreadsheet (Calc), a presentation application (Impress), a drawing application (Draw), a formula editor (Math) and a database management application (Base)
Mozilla’s Firefox
Firefox is Mozilla's next-generation open source web browser. Firefox's features include a popup blocker, tabbed browsing, a smarter search, better security and privacy options, hassle-free download manager, and much, much more.
Audacity is a free and open-source digital audio editor and recording application software, available for Windows, mac OS, Linux, and other Unix-like operating systems.
GIMP
GIMP (GNU Image Manipulation Program) provides the tools needed for high-quality image manipulation. From retouching to restoring to creative composites, the only limit is your imagination. GIMP gives artists the power and flexibility to transform images into truly unique creations.
VLC
VideoLAN Client (VLC) is a free and open-source cross-platform multimedia player and framework that plays most multimedia files as well as DVDs, Audio CDs, VCDs, and various streaming protocols.
"Computer Fundamentals for Standard VII and VIII" is a vital educational resource that equips young learners with essential digital skills, setting a strong foundation for their technological journey ahead.
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