1. Basic concepts of Information technology
By: Norah Alsufyan
Basic concepts of Information technology
Ch:4

2. Contents Computer concept Types of Computer Data Representation
By: Norah Alsufyan
Contents
Computer concept
What is computer ?
What does a computer do ?
Characteristics of Computers
Types of Computer
Microcomputers
Midrange computers
Mainframes
Supercomputers
Data Representation

3. Contents Computer System Hardware Software
By: Norah Alsufyan
Contents
Computer System
Hardware
Computer Hardware Components
System unit
CPU
Memory
Storage
Input and output
Software
System software
Application software
How Software is Made
The Graphical User Interface (GUI)

4. By: Norah Alsufyan
Computer concept

5. By: Norah Alsufyan
What is a Computer?
The term computer is derived from the Latin word compute, which means to calculate.
A computer is an electronic device that accepts information and instructions from a user, manipulates the information according to the instructions, displays the information in some way, and stores the information for retrieval later.

6. What does a computer do? AB à C = A + B C Input Processing output
By: Norah Alsufyan
What does a computer do? AB à
C =
A + B C
Input Processing output

7. Characteristics Of Computers
By: Norah Alsufyan
Characteristics Of Computers
The main characteristics of computers are:
Speed
Computers are capable of carrying out the task with enormous speed
Storage
Computers can store enormous quantity of information.
These large volumes of storage occupy much lesser space compared to paper documents
Accuracy
The accuracy of a computer is consistently high.
The accuracy of the computer is best achieved by programming them in the most efficient manner
a) Speed :
Today’s computers, according to their class, can perform from 4 MIPS (Millions of instructions per second) to 100 MIPS. What may take days for manual
calculations may take only a few hours for computers to perform. Inside the computer the information signal travels at incredible electronic speed.
b) Storage:
Computers can store enormous quantity of information. Which is expressed in terms of Kilobytes (or) Mega Bytes (MB) or Gega Bytes (GB). It is achieved through its ‘Main memory’ or ‘Primary storage’ and through ‘auxiliary storage’ or ‘Secondary storage’. The Hard disks Floppy disk, Compact Disc(CD) and Magnetic Tape storage are examples of secondary storages. These large volumes of storage occupy much lesser space compared to paper documents and this aspect of computers makes them more powerful.
c) Accuracy:
The accuracy of a Computer is consistently high. In fact, this quality of the computers m
ake them indispensable in various fields such as Scientific Research, Space Research, Weather
Predictions and many other areas where precision of a high or
der is required. The accuracy o
f the
computer is best achieved by programming them in the most effici
ent manner. When it comes to
very complex mathematical or scientific problem the computer’s accuracy has no substitute. d)
Versatility:
Computers are versatile in that they can perform almost any task, provided they are given
the appropriate logical step
s. For example, they are capable of performing wide ranging tasks
such as construction of a payroll, inventory management in a factory, hotel billing, hospital
management, banking applications and any imaginable task in every walk of life. e)
Automation:
The biggest advantage of computers is that it is automatic in its operation. Once a programming
logic is initiated the computer performs repeated operations without human interventions until
program completion. f)
Diligence:
Computers are machines and
that do not get tired or ‘lose concentration’ like human
beings. If a large number of calculations say million calculations are to be performed the
resultant output will remain exactly the same even if operations are repeated any number of
times. But when
a human being is asked to do the same job this consistency cannot be achieved.
This watermark does not appear in the registered version - 3
Thus for those who want consistent and continuous standard output, computer’s ‘diligence’ is of
great hel

8. Characteristics Of Computers
By: Norah Alsufyan
Characteristics Of Computers
Versatility
Computers are versatile in that they can perform almost any task, provided they are given the appropriate logical steps.
Automation
The biggest advantage of computers is that it is automatic in its operation.
Once a programming logic is initiated the computer performs repeated operations without human interventions until program completion.
Diligence
Computers are machines and that do not get tired or ‘lose concentration’ like human beings.

9. Types Of Computer Computers come in four sizes: Microcomputers
By: Norah Alsufyan
Types Of Computer
Computers come in four sizes:
Microcomputers
Midrange computers
Mainframes
Supercomputers

10. By: Norah Alsufyan
Types Of Computer
Microcomputers: is a small, relatively inexpensive computer ,the most common of all, easily outsells all other types of computers annually for use in business and at home.
Five types of Microcomputers:
Desktop Computers
Notebook Computers/Laptop Computers
Tablet
Handheld computer , such as : smartphone

11. By: Norah Alsufyan
Types Of Computer
Mainframes are a type of computer that generally are known for their large size, amount of storage and processing power.
More powerful and larger than a microcomputer.
Primarily used by large organizations for mission-critical applications requiring high volumes of data processing , such as census , consumer statistics and financial transaction processing.
Midrange computers is a computer smaller than a mainframe, but larger than a microcomputer.
A medium-sized computer
Computers that are more powerful and capable than microcomputer computers but less powerful and capable than mainframe computers.

12. By: Norah Alsufyan
Types Of Computer
Supercomputers: The most powerful and largest computers
Supercomputers were designed to solve problems consisting of long and difficult calculations.
Example: NASA and Weather forecasting

13. By: Norah Alsufyan
Data Representation
Data representation refers to the internal method used to represent various types of data stored on a computer.

14. By: Norah Alsufyan
Data Representation
Data refers to the words, numbers, figures, sounds, and graphics that describe people, events, things, and ideas
Binary digits (bits) value is either 0 or 1
A series of eight bits (8 bits) is called a byte
Kilobyte (KB or K) = 1024 bytes
Megabyte (MB) = approx. one million bytes
Gigabyte (GB) = approx. one billion bytes
Terabyte (TB) = approx. one trillion bytes
ASCII – American Standard Code for Information Interchange

15. Computer System A computer system consists of : hardware software
By: Norah Alsufyan
Computer System
A computer system consists of :
hardware
software

16. By: Norah Alsufyan
Computer System
System: A set of components that interact to accomplish a purpose.
A computer system consists of two major elements which are complement each others:
Hardware refers to the physical components of a computer
Example : mouse , CPU, memory and monitor.
Software refers to the intangible components of a computer system, particularly the programs, or lists of instructions, the computer needs to perform a specific task
Example : Windows and Microsoft word.

17. Hardware and Software are Complement Each Other
By: Norah Alsufyan
Hardware and Software are Complement Each Other
We can equate hardware and software with human body and human intelligence, respectively.
All human physical actions such as walking and eating are based on the thoughts and feelings, which is raised by the brain.
If the brain does not raise thoughts and feelings, we do not perform any physical activity. Similarly, the actions and functioning of every hardware equipment is driven by software.
The combination of physical equipment (hardware) and logical instructions (software) gives modern computing system their power and versatility.
The computer performs operations like addition, subtraction, multiplication and division only when the user instructs it to do so.
The user issues instructions and the CPU acts in accordance with the instructions.
The sets of instructions, which control the sequence of operations, are known as programs , and collectively programs are called software.

18. By: Norah Alsufyan
Hardware
Physical components of a computer

19. Computer Hardware Components
By: Norah Alsufyan
Computer Hardware Components
A typical computer is made up of:
The motherboard is the main electronic component of the computer
System Unit
Input devices and output devices
Multimedia Devices
Computer hardware designed to display, store, record or play multimedia content such as photos, music and videos.
Types of multimedia devices include microphones, speakers, cameras and headphones.

20. System Unit The central component of the system
By: Norah Alsufyan
System Unit
The central component of the system
The Processor: corresponds to the CPU
Memory: RAM and ROM
Storage: Hard Disk or Removable Storage devices

21. By: Norah Alsufyan
The Processor (CPU)
A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program.
This unit performs processing of instructions and data
CPU is your computers brain.
The processor tells your computer what to do and when to do it.
Does the calculations
Speed is very important – measured in megahertz (MHz): the faster the processor the more calculations performed per second.

22. By: Norah Alsufyan
Memory
Memory is any physical device capable of storing information temporarily or permanently.
Measured in bytes
 One byte = eight bits
 Types of memory:
Random Access Memory (RAM) : Volatile memory
Cache memory(RAM cache or CPU cache) : - Volatile memory
Virtual memory: Volatile memory
Read-only memory(ROM) : nonvolatile memory

23. Types Of Memory Random Access Memory (RAM)
By: Norah Alsufyan
 Types Of Memory
Random Access Memory (RAM)
Used by the Computer as the working area
Holds the working program, the data being processed and the interim results
Volatile - contents are erased if power is cut
Can be accessed randomly: can get any piece of data directly.
Faster than permanent storage
Not to be confused with ROM (Read-Only Memory)

24. Types Of Memory Cache memory (CPU memory)
By: Norah Alsufyan
 Types Of Memory
Cache memory (CPU memory)
Cache memory is random access memory (RAM) that a computer microprocessor can access more quickly than it can access regular RAM.
This memory is typically integrated directly with the CPU chip or placed on a separate chip that has a separate bus interconnect with the CPU.
Volatile - contents are erased if power is cut
Virtual memory
Virtual memory meant the idea of using disk to extend RAM.

25. Types Of Memory Read-only memory(ROM)
By: Norah Alsufyan
 Types Of Memory
Read-only memory(ROM)
Once data has been written onto a ROM chip, it cannot be removed / modified and can only be read since these instructions do not need to be changed very often.
Read-only memory (ROM) contains the instructions for what needs to happen when a computer is powered on.
Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.

26. By: Norah Alsufyan
Storage
Saved permanently- records and stores all programs and data / information
Types of Storage media
Hard Disk
Optical storage device
- CD – DVD – CD-R
– CD-RW –DVD-RW – DVD-R – CD-ROM
Flash memory
Flash memory cards
USB flash storage device

27. By: Norah Alsufyan
Input and Output
The data or instructions you type into the computer are called input
The result of the computer processing your input is referred to as output
Peripheral devices accomplish input and output functions

28. By: Norah Alsufyan
Input Devices
You use an input device, such as a keyboard or a mouse, to input data and issue commands
– Keyboard
– Pointing device :controls the pointer
Mouse
Trackball
Touchpad
Pointing stick
– Touchscreen
– Scanner

29. Output Devices Output devices show you the results of processing data
By: Norah Alsufyan
Output Devices
Output devices show you the results of processing data
Monitor
LCD
LED
Printer
Laser
Inkjet
Dot matrix

30. By: Norah Alsufyan
Software
Intangible components of a computer system

31. Software Generic name of all programs
By: Norah Alsufyan
Software
Generic name of all programs
Made up of code interpreted by the hardware
Written in programming languages - Java, C and C++
Two kinds of Software:
System
Application

32. By: Norah Alsufyan
System Software
System software helps the computer carryout its basic operating tasks.
Example of System software is Operating System (OS)
The operating system is a software program that acts as an interface between the user and the computer
OS is used to control and manage the hardware components such as keyboard, monitor, printer, etc.
OS the driving program of the computer
– OS has Multitasking features
–  communicates between all programs and the hardware
–  manages data to ensure security and integrity
–  Examples: Windows, Mac OS, Unix

33. System Software The basic functions of an operating systems are:
By: Norah Alsufyan
System Software
The basic functions of an operating systems are:
Process Management:
It handles the creation, deletion, suspension, resumption, and synchronization of process.
Memory Management:
It handles allocation and de-allocation of memory space as required by various programs.
File Management:
It is responsible for creation and deletion of files and directories. It also organizes, stores, retrieves, names, and protects all the files.

34. System Software The basic functions of an operating systems are:
By: Norah Alsufyan
System Software
The basic functions of an operating systems are:
Device Management:
It manages all the devices of the computer system such as printers and modems. If any device fails, it detects the device failure and notifies the same to the user.
Security Management:
Protects system resources and information against destruction and unauthorized use.
User interface:
Provides the interface between the user and the hardware

35. Applications Software
By: Norah Alsufyan
Applications Software
Application software enables you to perform specific computer tasks, such as document production, spreadsheet calculations, and database management
Used for the things you want the computer to do
Common Examples - Word, Excel, Internet Explorer

36. By: Norah Alsufyan
How Software is Made
Involves a cycle of research, analysis, development and testing
Systems Analysts - study the business processes and designs the software
Programmers - develops the software

37. The Graphical User Interface (GUI)
By: Norah Alsufyan
The Graphical User Interface (GUI)
Represents all the program / computer resources as icons
Workspace represented graphically
More usable: led to wider use of computers

38. By: Norah Alsufyan
Conclusion
Computer is an electronic device that performs diverse operations with the help of instructions to process the information in order to achieve desired results.
Speed, accuracy, versatility, diligence , storage and automation characterize the computers.
There are different type of computers : Microcomputers , Midrange computers , Mainframe and Supercomputers.
Supercomputers is the most powerful and largest computers.
A series of eight bits (8 bits) is called a byte
A computer system consists of hardware and software
The Processor, Memory: and Storage are the system unit.

39. By: Norah Alsufyan
Conclusion
A central processing unit (CPU) carries out the instructions of a computer program.
There are four types of memory : RAM, ROM , cache and virtual memory.
RAM, ROM , cache and virtual memory are volatile memory , whereas ROM is nonvolatile memory
There are four types of Storage media : Hard Disk, Optical storage device , Flash memory.
The data or instructions you type into the computer are called input
The result of the computer processing your input is referred to as output
There are two kinds of Software: System and Application

40. Revision Explain what does a computer do by drawing ?
By: Norah Alsufyan
Revision
Explain what does a computer do by drawing ?
… is the most powerful and largest computers
Microcomputers
Midrange computers
Mainframes
Supercomputers
… is a small, relatively inexpensive computer ,the most common of all computers.

41. By: Norah Alsufyan
Revision
Desktop Computers is type of midrange computers (Ture – false)
Smartphone is type of handheld computers (Ture – false)
Tablet is type of Microcomputers computers (Ture – false)
Laptop Computers is type of mainframes computers (Ture – false)
… is a computer smaller than a mainframe, but larger than a microcomputer.
… value is either 0 or 1
A series of eight bits (8 bits) is called a …
A computer system consists of … and

42. By: Norah Alsufyan
Revision
A set of components that interact to accomplish a purpose.
… refers to the physical components of a computer
… refers to the intangible components of a computer system
… lists of instructions, the computer needs to perform a specific task
Gigabyte (GB) =
1024 bytes
one million bytes
one billion bytes
one trillion bytes

43. Revision Every software is driven by hardware equipment (Ture – false)
By: Norah Alsufyan
Revision
Every software is driven by hardware equipment (Ture – false)
CPU is an example of software (Ture – false)
RAM carries out the instructions of a computer program (Ture – false)
Random Access Memory (RAM) is non volatile memory (Ture – false)
Read only Memory (ROM) is volatile memory (Ture – false)
The central component of the system (system unit)
Memory , monitor and storage
Storage , Memory and CPU
Memory and CPU and mouse

44. By: Norah Alsufyan
Revision
Cache memory is actually random access memory (RAM) (Ture – false)
Cache memory meant the idea of using disk to extend RAM (Ture – false)
… The data or instructions you type into the computer .
… The result of the computer processing your input
… accomplish input and output functions
Give 2 examples of input and output devices ?

45. By: Norah Alsufyan
Revision
There are two kind of software which are … and
… helps the computer carryout its basic operating tasks.
… enables you to perform specific computer tasks
… is a software program that acts as an interface between the user and the computer
Write 3 basic functions of an operating systems?
… Represents all the program / computer resources as icons
… is used to control and manage the hardware components such as keyboard, monitor, printer, etc.
… the driving program of the computer