COMPUTER AWARENESS
1. COMPUTER
Introduction:
Origin of word Computer – Latin Word – ‘Computerac’ which means to compute and to calculate.
Five Generations:
Generation / Period / Main Electronic Components / Main Computers / Operating SystemI / 1940-56 / Vacuum Tubes, Flip Flops / UNIVAC, ENIAC / Mainly Batch
II / 1956-63 / Transistors / IBM-700, IBM-1401 / Time Sharing
III / 1963-71 / Integrated Circuits / IBM-1620, ATLAS / Real Time Sharing
IV / 1971-Present / uProcessors, LSI / NCR-395, APPLE / Time sharing nw
V / Present and Beyond / Optical Fibre, Artificial Intelligence, VLSI, VVLSI / NA / NA
British Scientist – Charles Babbage is father of Modern Computer by conceived an automatic calculator of computer in 1833.
Types of Computer:
1. Micro Computer – Used by Individuals. Otherwise called as PC, Laptops, Tablets and Desktops
2. Mini Computer – Comparatively larger and 5 to 50 times powerful than micro computer
3. Main Frame Computer – Large sized computers. Time Sharing and Multi Tasking even more than 100 people can work together. Used in Scientific and Research based Projects
4. Super Computer – More powerful in terms of Their Storage capacity, efficiency and output ratio. Most efficient and fastest computer
5. Quantum Computer – Computer binary bits will be replaced with Q-bit and efficiency comparable to the human brain
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3 4
Components of Computer:
1. Input Unit
Instructions and Data to a computer. Eg: Keyboard, Mouse, Light Pen, Joy Stick, Bar Code Reader, Smart Card Reader, Touch Screen, Microphone, Digital Camera, Scanner
2. Central Processing Unit (CPU)
Instructions and Data manipulated and processed inside CPU
Parts of CPU:
ALU: ALU performs all arithmetic and Logic Operations. It consists of no. of small location termed as registers.
Control Unit: command to transfer data from the input devices to memory and memory to ALU. It transfers the results from memory to output devices.
Memory: It holds all the raw and processed data, set of instruction and information inside the CPU.
Random Access Memory – Volatile memory that holds data and code
Read only Memory – Non Volatile Memory it means it can keep data even without a power source
Cache Memory – accessed much faster than conventional RAM
3. Output Unit
Result of processing and displays results to user
Eg: Monitors, Printers, Speakers, Pen drives, etc.,
Software
Set of instructions that directs computer to process information.
Types of Software:
1. System Software – coordinates the operation of the various hardware components of the computer such as Operating system. Eg: DOS, Windows, UNIX and LINUX
2. Application Software – Set of program designed for specific uses of applications.
3. Utility Software – debug the software errors; correct the data through the editor and sort data eg: pkzip, Anti-virus software, Tune Up.
Some units with size
Hardware – seen by eyes and felt by touching
Firmware – combination of both Hardware and software eg: BIOS (Basic Input and output System)
Liveware – users working on the systems
Operating System
Is a software or series of programme, which performs various types of functions in order to manage and organize files
OS can be classified as
Multi User – two or more users to run programs
Multi Tasking – more than one programme
Multi Processing – running a programme on more than one CPU
Multi Threading – allows different users to operate single programme concurrently
Multi Time – real time based applications like satellite launch, weather-forecasting
Programming Language:
Computer can directly execute its machine language.
Assembler:
Assembler is a computer program which is used to translate program written in Assembly Language into machine language. The translated program is called as object program.
Compiler:
A compiler is a program that translates a programme written in High Level Language to executable machine language. The process of transferring HKK source program in to object code is a lengthy and complex process as compared to assembling.
Interpreter:
The basic purpose of interpreter is same as that of complier. In compiler, the program is translated completely and directly executable version is generated. Whereas interpreter translates each instruction, executes it and then the next instruction is translated and this goes on until end of the program.
Generations:
1st Generation – Fortran (Formula Translator)
2nd Generation – Fortran ii, Algol – 60, Cobol (Algol- Algorithmic Language, Cobol – Common Business oriented Language)
3rd Generation – Pascal, Basic, C (Basic – Beginners all purpose symbolic instruction code)
4th Generation – oracle, EDA
5th Generation – Artificial Intelligence
Some programming languages Abbreviations
1 . HLL – High level Language
2. Prolog – Programming in Logic
Low Level programming language – little or no abstraction from a computer’s microprocessor. Reduced amount of abstraction between the language and itself and closer to hardware
High Level Programming language – more user friendly, platform independent and abstract from low-level computer processor
Very high level Programming language – very high level of abstraction, profession programmer productivity tool.
abstraction - a concept or idea not associated with any specific instance
Microsoft Office
MS Word – Word processing applications
MS Excel – Spreadsheet application
MS Powerpoint – presentation graphics software
MS Access – relational database management system
Internet and Networking
Internet or NET – Worldwide, Publicly accessible system of interconnected computer networks that transmit data by packet switching using standard Internet Protocol (IP)
Network of Network
Important Protocols used over internet
Hypertext Transfer Protocol – simple text which can be written, edited and modified
Transmission control Protocol/Internet Protocol – Networking protocol to connect the computer on remote locations and makes exchanges of information
Point to point protocol – dial account puts your computer directly on the internet (has its own name and IP address)
File Transfer Protocol – exchanging files over any network
Internet Protocol suit – set of communication protocols
Internet Service provider – Business firm or organization that offers users access to the internet and related services
Network Service provider - Business firm or organization that sells bandwidth or network access
IPv4 – Internet Protocol Version 4 – 32 Bit address
IPv6 – Internet Protocol Version 6 – 128 Bit address
Terminology
WWW – World Wide Web – aims to provide universal access to a large universe of documents
Web Server – programme that using the client/server model
Client Server – network architecture which separates the client from the server
Proxy Server – offers a computer network service to allow clients to make indirect network connections to other network services
Website – collection of web pages
Webpage –resource on WWW, usually in HTML/XHTML format – which enable to navigation from one page to another
Web browser – application package to run over the client computer to connect it with the server. Eg. Internet explorer, chrome
Uniform Resource Locator (URL) – another name of web address
Android – Operating System for mobile – version of Linus kernel
Wireless Application protocol (WAP)- web browser for small devices such as cell phones
E-mail – messages are an electronic medium – E-mail are usually encoded in American Standard code for Information Interchange (ASCII) – Used Simple mail transfer Protocol
Networking
Communication between groups of systems.
LAN (Local Area Network), MAN (Metropolitan Area Network) and WAN (Wide Area Network)
Types of LAN
Types of WAN
Security Threats:
Phishing – form of criminal activity using social engineering techniques – getting information such as passwords, credit card details etc
Computer worm – self replicating computer programme that allocates more space in system
Spam – abuse of messaging systems – bulk emails.
Mobile Phone Spam – Text messaging service – irritate the consumers
Computer Virus – attaches itself to and becomes part of another executable programme
Eg: Creeper, Mellissa, I Love you, Code Red, Nimade
Types
Malware – superset of computer viruses, worms, Trojan horses, rootkits and other malicious and unwanted software
Adware- advertising supported software
Spyware – spying your information which installed on system
Anti Virus – opposite function of Virus
Firewall – Software of hardware based device to permit or deny network transmissions based on a set of rules.
Questions and Answers
1. In a computer system ...... device is functionally opposite of a keyboard
Ans: Printer
2. CGI stands for?
Ans: common gateway interface
3. How far do u know ?
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¤ 1 Bit = Binary Digit
¤ 8 Bits = 1 Byte
¤ 1024 Bytes = 1 Kilobyte
¤ 1024 Kilobytes = 1 Megabyte
¤ 1024 Megabytes = 1 Gigabyte
¤ 1024 Gigabytes = 1 Terabyte
¤ 1024 Terabytes = 1 Petabyte
¤ 1024 Petabytes = 1 Exabyte
¤ 1024 Exabytes = 1 Zettabyte
¤ 1024 Zettabytes = 1 Yottabyte
¤ 1024 Yottabytes = 1 Brontobyte
¤ 1024 Brontobytes = 1 Geopbyte
¤ 1024 Geopbyte=1 Saganbyte
¤ 1024 Saganbyte=1 Pijabyte
4. C is a Structured Programming Language.
Pascal is a procedural Programming Language.
C++,Java, Small-talk, Objective-C,C#.. is a Object Oriented Programming..
Prolog, Datalog is a Logic Programming.
Spreadsheet like that is End user Programming.
5. A...... is the term used when a search engine returns a web page that matches the search criteria.
Ans: hit
6. Which device is used as the standard pointing device in a Graphical User Environment?
Ans: Mouse
7. What is the name given to the organized collection of software that controls the overall operation of a computer?
Ans: Operating system
8. Data or information used to run the computer is called?
Ans: Software
9. To memories the e- mail address one should use?
Ans: Add book
10. A Hardware device that converts data into meaningful information
Ans: Processor
11. What from the following refers to the people, related to computing process?
Ans: Human ware
12. Which of the following is not an example of storage device?
Ans: RAM
13. Today, the common form of RAM is built from?
Ans: Semiconductors IC's
14. Benefit of DRAM is ___
Ans: It is cheaper than SRAM
15. Which element is appropriate for the set of instructions, by which computer performs more than one task?
Ans: Software
16. Which of the following is both output and input?
Ans: monitor
IMPORTANT TERMINALOGIES AND ABBREVIATIONS:
01. Access:To store or retrieve data
02. Add-on:Circuits, systems, or hardware devices that can be attached to a computer to increase its memory or improve itsperformance
03. Application: A system, such as a payroll, that has been defined to be suitable for electronic data processing techniques
04. Archived file: A file that has been transferred to a lower level in the memory hierarchy, usually from magnetic disc to magnetic tape, may be as a result of operations of appropriate resource management
05. Array: A group of two or more logically related elements identified by a single name; generally stored in consecutivestorage locationsin main memory
06.Audit trail: A permanent record of every transaction taken by a computer system, indicating for example, when users log in and out, what transaction they perform, when files are accessed and the type of access. Examination of this record provides a way of observing patterns of security violation and/or serves as a deterrent to violations
07. Availability:The ratio of time a device is operating correctly to the total scheduled time for operating
08. Back office operations: Operation that does not involve direct interaction with customers
09. Back up:A resource that is, or can be used as a substitute when a primary resource fails or when a file has been corrupted
10. Bar code:A printed machine readable code that consists ofparallel barsof varied width and spacing. The application most commonly observed is the coding on food and goods that is read at the checkout and translated into a line of print on the bill showing product and cost
11. Batch processing: A method of organizing work for a computer system, designed to reduce overheads by grouping together similar jobs
12. Bit: Contraction of binary digit
13. Bug: An error or mistake in a programme
14. Byte:A group of consecutive bits forming a unit of storage in the computer and used to represent one alphanumeric character; a byte usually consists of 8 bits but may contain more a fewer bits depending on the model of computer
15. Character: An alphabetic letter, a digit or a special symbol
16. Chip: A small section of a single crystal of semiconductor usually silicon, that forms thesubstrate upon which is fabricated a single semiconductor device or all the individual devices comprising an integrated circuit
17. Configuration: The particular hardware elements and their interconnection in a computer system for a particular period of operation
18. Debug: To trace and correct errors in programming code or hardware malfunctions in a computer system
19. Downtime: The percentage of time that a computer system is not available for use
20. Dummy: An artificial instruction, address etc. used only to fulfill specification in a programme but not actually performing a function
21. Duplex channel: A communication channel that allows data to be transmitted in both directions simultaneously
22, Encoder: A small table-top electronic machine which is a combination of electronic typewriter and calculator – functions: encode numeric data in the MICR in desired font; print a listing of amounts of all instructions with batch/grand totals; zero-proofing place clearing endorsement, stamp on the reverse of instruments
23. Image: A copy in memory of data that exists elsewhere
24. Interface: A common boundary between two systems, devices or programmes
25. Lock: A key or other group of characters that allows access to specifiedstorage locationsor software systems
26. Log-in: To enter the necessary information like personalidentification number– PIN and/or password to begin a session on a terminal
27. Menu: The list of options may be displayed with a sign code opposite each. The selection may then be made by keying the single code. The method provides simple way of guiding a user through a complex situation by presenting a sequence of simpler decisions