related to comupter subject

1. CLASS – 4
SUBJECT – COMPUTER
CHAPTER - 1
LET US REVISE

2. Computer is made up of many parts. These parts
together form the computer system.
CPU
CPU stands for Central Processing Unit. It is called
as the brain of the computer.
MONITOR
Monitor displays the output we receive from the
computer. It looks like a television Screen.
KEYBOARD
Keyboard is used to input data into the computer
through typing. To type or write on the computer,
you need to press the key you need.

3. MOUSE
Mouse is a pointing device that helps in working
on the computer. An arrow displayed on the
monitor represents the mouse-position.
UPS
UPS stands for Uninterrupted Power Supply. It has
a rechargeable battery and it is directly connected
to the power supply.
PRINTER
A printer is used to print any document or picture
on a sheet of paper.

4. SPEAKER
A speaker is used to listen to music and other
sounds playing on the computer.
MICROPHONE
Microphone is used to record any voice on the
computer. You can also use it to talk on the
internet.

5. HARDWARE
The physical components or parts of a computer that you can
see or touch/feel are known as hardware. The parts of
computer that you see in the computer lab like keyboard,
monitor, CPU and printer are examples of hardware.
SOFTWARE
The applications and programs that help the computer system
perform the tasks given by the user are known as software.
Computer hardware cannot function without software. You
cannot see or touch/feel the software.

6. Computer software can be divided into
System Software and Application
Software.
System Software
The type of software that controls the
working of the computer is called system
Software. A computer system will not
function properly without System
software.

7. Application Software
This type of software is designed to suit the
needs of the user. Depending upon its usage,
Application software can be divided into
two types General Purpose Software and
Special Purpose Software. MS Word, MS
Paint, Calculator etc. are some examples of
Application Software.

8. Assignment:
A. Answer the following questions:
a.) Define UPS.
b.) Write difference between hardware and software.
c.) Define System Software and Application Software.

9. TUX PAINT
Tux Paint is a drawing application for children. With this we can not only
draw the pictures, we can add sound effects too. It has a simple and easy
to use interface.
Drawing Tools
There are various types of drawing tools present in Tux Paint. Let us
discuss some of them.
New tool shows various background colours and starter pictures to start a
new drawing.
Open tool is used to open the saved pictures. You can select the picture
from the pictures shown.

10. Paint tool is used for freehand drawing. It works like a pencil.
Lines tool is used to draw straight lines of different shapes.
Brush shapes is used to give freehand stroke to the image. There are
various brush shapes and sizes present in tux Paint. Depending upon
the use, you can select the type and size of brush.
Eraser tool is used to erase the drawing or any part of it.
Stamp tool is just like a rubber stamp or a sticker. Tux Paint
supports hundreds of predefined images and cartoons.

12. INTRODUCTION TO WINDOWS 7
As we know that, Windows is one of the most popular
operating system. It is a Graphical User Interface (GUI)
based operating system that enables you to start the
system, manage various devices, administers your files
and allocate computer resources judiciously. The first
screen that you see on switching on the computer is the
Desktop. The Desktop has these parts- Desktop
background, lcons, Taskbar and Start Button.

13. Wallpaper in Windows is the picture on the background area of the
Desktop. You can apply your own picture or select from the Windows
Gallery.
A Screen saver is a picture, animation or animated text which appears on
the screen when the computer is not used for a while (idle). By setting up
the Screen saver with Password protection, we can also secure our computer

15. MICROSOFT PAINT
It helps you to create and edit your drawings. You can open Paint
in many ways through Start menu or through a shortcut on your
Desktop.

17. Assignment:
A. Answer the following questions:
a.) Describe the Drawing tools of Tux Paint:
Stamp Tool, Paint Tool, Eraser Tool.
b.) Write about Windows – 7.
c.) Define Wallpaper and Screen Saver.