1. CRITICAL UNDERSTANDING OF ICT: Engagement with the Field/Practicum
BY Arijit Gupta

2. COMPUTER :  Computer is an electronic machine which processes raw data to give meaningful informations. It accepts information(in the form of digitalized data) and manipulates it for some result based on a program.
Characteristics Of Computer
 1. SPEED   : Computer is very fast calculating device.
 2. ACCURACY   : Computer always gives accurate results.
 3. STORAGE CAPACITY   : Computer have a very large storage capacity.
 4. VERSATILITY   : The working of computer with different types of data is known as versatillity.
 5. DILLIGENCE   : A Computer can work for long hours with the same accuracy and speed.
 6. NO THOUGHTS   : Computers have no thoughts or emotions.

3. CLASSIFICATION OF COMPUTERS
Present day, Computers can be classified into three major categories             1. Analog Computers:-Analog computers are based on the measuring of analog value. These are worked on analog signal.  Analog computers are used to process information of a physical nature as temperature, pressure, electric current etc. Examples: AKAT-1, ELWAT.
            2. Digital Computer:-Digital computers are based on the binary signals i.e., 0 & 1. Digital computers process raw data and convert it into meaningful information.
            3. Hybrid Computers:-Hybrid computers are the mixture of Analog & Digital computers.

4. Computers can be classified on the basis of size & speed
1. Micro Computer.
  2. Mini Computer.
3. Main-Frame Computer.
  4. Super Computer.
The above four computer are digital computers.

5. Computer Generations First Generations : Time-Period : 1942 To 1955
  Technology Used           :  Vaccum Tubes
  Memory Capacity          : 10,000 To 20,000 Bytes
  Execution Speed            : Few Thousands IPS
  Languages                       :  Machine Language
  Important Computers  :  
UNIVAC-1,UNIVAC- 2, IBM-170,IBM-650

6. Second Generations of Computers
Time-Period                   : 1955 To 1964.
  Technology Used          : Transistors , Diode.
  Memory Capacity         : 4,000-64,000 Bytes.
  Execution Speed           : Upto 1 Million IPS.
   Languages                      : Assembly, FORTRAN, COBOL & ALGOL.
 Important Computers : CDC-60, UNIVAC & IBM-1620

7. Third Generations of Computers
   Time-Period           : 1964 To 1975
 Technology Used    : ICs with SSI , MSI
 Memory Capac        : 32,000 To 4 MB.
 Execution Spee        : Upto 10 MIPS
 Languages                 : FORTRAN, PL-
1 & BASIC.
 Important Computers : IBM-360 & UNIVAC-100

8. Fourth Generations of Computers
Time-Period                   : 1975 To 1989.
   Technology Used          : ICs with VLSI, processor.
    Memory Capacity         : 51,200 To 32MB.
    Execution Speed           : Upto 100 MIPS.
    Languages                      : C, C++
    Important Computers : Apple-II, TRS-80, VAX-9000 & IBM-PC.

9. Fifth Generations of Computers
Time-Period                   : 1989 To Today
   Technology Used          : ICs with ULSI, MCP.
   Memory Capacity         : Upto 32 MB.
   Execution Speed           : Very Fast.
   Languages                      : JAVA, XML.
   Important Computers : Dell Vostro-1015, Sony, Compaq,

10. Organisation of Computer System
INPUT DEVICES.
(EXAMPLE)
A. KEYBOARD.
B. MOUSE.
MEMORY DEVICES.
1. PRIMARY MEMORY.
2. SECONDARY MEMORY
CPU (ALU+CU)
OUTPUT DEVICES.
A. PRINTER.
B. PLOTTER.

11. MEMORY : Memory is a device or medium that can accept data, hold data and deliver data on demand at a later time.
SECONDARY MEMORY
PRIMARY MEMORY
Primary memory is volatile that means it loses information in it as soon as the computer system switches off or resets. It is also known as MAIN MEMORY.
 EX- RAM ,ROM
Secondary memory is non-volatile that means it can retain data when the computer system resets or switches off. It has slower speed , high capacity in operations than primary memory.  It is  AUXILARY MEMORY.
EX : Hard disk,
Memory Card .

12. TYPES OF PRIMARY MEMORY
RAM
ROM
It is of two types-:
           1. Static RAM
           2. Dynamic RAM
              STATIC RAM : Static RAM costlier & consume more power consisting of flip-flops that store binary information. It is easier to use and has shorter read and write cycles which means high-speed.   DYNAMIC RAM : Dynamic RAM is a type of RAM that uses an external circuitry to periodically "regenerate" or refresh the storage charge to retain the stored data.
Cache memory are those memory which are used to increase up the speed CPU.
PROM:- Programmable Read Only Memory is used to store program in a computer but it can write program only once. EPROM:-Erasable Programmable ROM can store computer program and also erase it. It can write program many time using U-V rays. EEPROM:- Erasable Programmable Read Only Memory can used to store the program and erase the small parts of the program. EAPROM:-Electrical Alterable Programmable Read Only Memory is used to store program like addition,subtraction,division mainly used in BIOS.

13. Computer stores data in binary format having smallest unit called binary digit(Bit)
o or 1
1 Byte
group of 8 Bits
1 Kilobyte
1024 Byte
1 Megabyte
1024 Kilobyte
1 Gigabyte
1024 Megabyte
1 Tetra byte
1024 Gigabyte

14. Types of Secondary Memory and its devices:-
Flash Drive/USB/Pen drive:- very small size and store large amount of data.
CD-ROM:- Compact Disk Read Only optical disk Memory to optically store the data.
Floppy Disk:-IBM introduce in 1970, Floppy disk are of 2 types (Mini & Micro Floppy).
Hard disk:-Magnetic disk is set of disk platters to store large amount of data at the range of GB or TB.
DVD:-Digital Video Disk or Digital Versatile Disk. It store large amount of data as compared to CD.

15. INPUT DEVICES
Keyboard:-SERIAL/ Parallel ONLINE input device having alphabets, numbers etc.
Mouse:- GUI mode Pointing device used to move the cursor on the screen. Types are Physical optical &cordless mouse.
Joystick:- Very popular game controller remote control unit .
Scanner:-Mainly used to check OMR sheets, also used to copy text, images in the form of soft copy.
Bar Code Reader(BCR):- Used in shopping malls to read the bar code and display the rate of item, to recognise courier products etc.

16. More input devices
Light Pen:- Pointing device to select a menu item or draw pictures on the monitor screen.
Track Ball:-Mostly used in notebook or laptop computer, instead of a mouse.
Digitizer:- Converts analog information into a digital form. convert a signal from camera to be stored in a computer.
Microphone:- used for applications like adding sound to a multimedia presentation or mixing music.
Magnetic Ink Card Reader (MICR):- used in banks because of a large number of cheques to be processed.
Optical Character Reader (OCR):-Used to read a printed text. OCR scans text optically character by character, converts them into a machine readable code and stores the text on the system memory.
Optical Mark Reader (OMR):-Optical scanner used to recognize the type of mark made by pen or pencil. Used for checking the answer sheets of MCQ.

17. OUTPUT DEVICES
VDU:- Visual Display Unit (plasma,LED,LCD) Resolution depends on number of pixels P inch.
Printer:-Printer is an output device which is used to show result in hard copy form or in paper form.
Plotter:-Produce high quality graphics in multiple colour.Used to create maps,charts etc. on a paper sheet.
Speakers:- Audio speakers as output device.
LCD Projectors:- To display image/video on giant screen

18. C. P. U. (CENTRAL PROCESSING UNIT) : is the brain of computer
C.P.U.(CENTRAL PROCESSING UNIT) :  is the brain of computer. All the actions performed by the computer system are initiated perform and controlled by C.P.U.
The sections of C.P.U are as follow:
1. A.L.U.(ARITHMETIC LOGIC UNIT) : The A.L.U. performs mathematical and logical operations. It
is one of the component of  C.P.U. of the computer 2. C.U.(CONTROL UNIT) : It manages and coordinates the operations of all its other components. It also controls the flow of data to and from memory or secondary storage devices. 3. MEMORY : Memory is a device or medium that can accept data, hold data and deliver data on demand at a later time.

19. Software is the combination of instructions to perform the specific task.
System Software:-System software controls the system and also used for run applications S/W. Ex:-DOS.
Application Software:-Application software are designed to perform a specific task. Ex:- Tally.

20. COMPUTER NETWORKS
In LAN, computers connect to each other with in a building, office, school , home within 0 to 5 Km.
In MAN, computers connect to each other in a city using HUB, repeater etc within Km.
In WAN, computers connect with in a broad geographical area. Formed from the combination of two or more MAN. In 2 cities, states or even countries.

21. Network Devices
A hub is a common connection point for devices in a network, used to connect segments of a LAN. A hub contains multiple ports.
A network bridge creates a single aggregate network from multiple communication networks or network segments.
Router chooses the shortest route for data communication to send packets. Feature is used in OSI model in network layer.
 Gateway is a node on a network that serves as an entrance to another network.
Firewall is a technique which is used to protect our private network from a public network i.e. Internet

22. MICROSOFT WINDOWS.
Windows makes it possible to complete all types of everyday tasks on your computer. You can use Windows to browse the Internet, check your etc.
Windows is also used in many offices because it gives you access to productivity tools such as calendars, word processors, and spreadsheets.
Microsoft released the first version of Windows in the mid-1980s. Recent ones include Windows 10(released in 2015), Windows 8 (2012), 

23. PARTS OF WINDOWS DESKTOP
Desktop refers to desktop environment, which is a Graphical User Interface metaphor that allows for interaction between the user and the operating system.
Some of the most common icons on the Desktop include those for My Computer, Recycle Bin, your Internet browser (e.g. Internet Explorer), and My Documents. On the Windows Desktop, you also have access to the Windows Start Menu through the Start button on the Taskbar, or Windows Notification Area.

24. WORKING WITH MY COMPUTER
My Computer is a section of Microsoft Windows first found in Windows 95 and included with all later versions that allows you to explore and manage the contents of your computer drives.
Using My Computer:- Once My Computer is open, you will see all available drives on your computer.
Finding files in My Computer :- Most files you create or will want to find are located in your My Documents folder.
Adjust system settings with My Computer:- To view your computer settings, right click on My Computer icon and then click Properties, steps opens your System Properties (the same window accessible through the Control Panel).

25. INTERACTIVE WHITE BOARD(IWB)
The first IWB were designed and manufactured for use in office. Developed by PARC around This board was used in small group meetings and round-tables. In 1991 Smart Technologies produced an interactive whiteboard that used projection technology.
Large interactive display in the form of a whiteboard. It can either be a standalone touchscreen computer or a connectable apparatus used as a touchpad to control computers from a projector. Used in board rooms, work groups, in training.

26. POPULAR APPLICATION S/W
Microsoft Office Word:- MS word comes under a package of MS office, helps to create professional looking documents. It contains reviews,font,page layouts, mailing etc.
Microsoft Office Excel:- MS Excel is the power full tool to manage data with ease. It contains cell,column,rows etc.
Microsoft Office PowerPoint:-MS PowerPoint, application S/W used for creating presentations containing ribbons, tabs etc.
Microsoft Office Access:- MS Access used to make process of creating database so easy.

27. FREE S/W FROM GOOGLE.
Google Docs, Google Sheets and Google Slides are a wordprocessor, a spreadsheet and a presentation program respectively, all part of a free, web-based software officesuite offered by Google within its Google Drive service.
The three apps are available as web applications, and as mobile apps for Android and iOS. The apps are compatible with Microsoft Office file formats. The suite also consists of Google Forms(survey software), Google Drawings(diagrammingsoftware) and GoogleFusionTables(database manager).

28. GOOGLE GROUP
Google Groups is a service from Google that provides discussion groups for people sharing common interests.
Google Groups became operational in February 2001, following Google's acquisition of Deja's Usenet archive. (Deja News had been operational since 1995.)
Google Groups offers at least two kinds of discussion group; in both cases users can participate in threaded conversations, either through a web interface or by .

29. BLOG AND BLOGGERS
The emergence of blogs in late 1990s coincided with the advent of web publishing tools that facilitated the posting of content.
Blog (weblog) is a discussion & informational  web published on the WWW of discrete, informal diary-style text entries ("posts“) displayed in reverse chronological order .
In the 2010s, "multi-author blogs" (MABs) have developed, with posts written by large numbers of professional authors.

30. THANK YOU