Introduction
A network is a set of inter connected devices, such as computers and printers. These devices are connected with transmission media or communication channel. Using network you can send and receive data from one computer another computer. You can also share various useful devices, such as printer and scanner. (See Figure. 6.3.1)
Depending on the way the computers are connected to a network, you can divide computer networks into the following categories:
Local Area Network (LAN)
LAN (Local Area Network) is a network which can be established in small area such as office, and college lab. LAN can be combination of interconnected two or more computers and a printer in office or lab. A LAN is useful for sharing hardware and ware resources. ICS (Internet Connection Sharing) software package is used to configure a local area network.
Wide Area Network (WAN)
(Wide Area Network) is one of the computer networks which can be established on a large geographical area. Internet is the best example of WAN. When you connect of computer with Internet, your computer automatically connect with all computers variety world which are already connected with Internet. Through WAN you can carry a variety of traffic types such as data, video and voice for long distance. Data services arc Telephone services are the most commonly used services of WAN.
Metropolitan Area Network
As here the name defining itself that a network which is in a particular metropolitan area, or can be denoted as a network with in an entire city is known as MAN (Metropolitan Area Network). One of the suitable example of this network is a cable connection, it's because the users are free to view number of channels at a particular time.
Internet is a global network that allows to carry a variety of traffic types such as data, video and voice for long distance. The Internet is an example of_________.
(A) LAN
(B) MAN
(C) WAN
(D) All of these
(E) None of these
Answer: (C)
Explanation
Correct Option:
(C) WAN is a wide area network that allows networking in unlimited area. Internet is the perfect example of WAN.
Incorrect Options:
(A) LAN is a local area network that allows small size networking.
(B) MAN is a metropolitan area network that allows networking in a city.
Computer Network is a combination of interconnected computers. They are three types LAN, WAN, and MAN. Cable connection is an example of_______.
(A) LAN more... 
How to draw a circle (Repeat Statement)
To draw a circle you need to use Repeat statement, as shown below:
REPEAT 360 [FD 1 RT 1] 
A Practical Approach to make a Pattern of a Watch on the LOGO Graphical Area.
A practical approach to make a pattern of watch in the LOGO program. To make a watch with second hand running is drawn in LOGO ring the following commands. To watch Pu rt 30 repeat 12 [fd 110 pd label repcount pu bk 110 rt 30] Px st setpensize [5 5] repeat 1000[fd 100 wait 40 bk 100 rt 6] After entering the given commands, press file menu to open the save and exit sub menu. Press save and exit to same the text box. After execution of the list of commands named as watch, LOGO draws the following pattern on the graphical area with one second hand running save as a watch's second hand runs.
Performing Arithmetic Operations
Logo allows performing the usual arithmetic operations. The result can be printed " Logo command window using the print statement. (See Figure. 6.2.3)
| Operations | Command |
| Addition | Print 5 + 38 |
| Subtraction | Print 8 - 44 |
| Division | Print 12/34 |
Which one of the following commands is used to move the direction of turtle to left 30°?
(A) ST30
(B) CS30
(C) RT30
(D) LT30
(E) None of these more... 
How to Change Screen Colour To change the screen colour you need to:
How to draw a Square
To draw a Square you need to use the following commands:
CS 
FD 100
RT90
FD 100
RT 90
FD 100
RT 90
FD 100
RT 90
How to draw a Triangle
To draw a triangle you need to use the following commands:
CS
RT 20
FD 100
RT 140
FD 100
HOME
END
How to draw an Equilateral Triangle
To draw an equilateral triangle you need to use the/allowing commands:
CS
FD 100
RT 120
FD 100
RT 120
FD 100 
Creating a line using Turtle
The FORWARD (FD) or BACK (BK) command is used to draw line. Along with the command, the number of steps is also given which determines the length of the line. FD 100J
FD 100
Moving the direction of the turtle to right or left
Logo enables the RT and LT commands that are used to move the direction of the turtle. Along with the command the angle is also given which determines how much the turtle is turned.
RT 60 
Note: sign indicates enter key 
LOGO Command List
The following table lists the shortcut that is used to perform various (See Figure. 6.2.1)
| SHORTCUT | INSTRUCTIONS | DESCRIPTION |
| CS | CLEARSCREEN | Allows clearing the picture before a new picture is drawn |
| ST | SHOWTURTLE | Allows showing the Turtle on the screen. |
| HT | HIDETURTLE | Hides the Turtle on the screen |
| PD | FORWARD Number | Allows moving the Turtle forwards according to the number indicated. |
| BK | BACK number | more...
 Introduction
Programming language enables you to write instructions which are understood by computer. There are various programming languages available, such as C, C++ and -3go. LOGO (Language of Graphic oriented) is a programming language that was developed to introduce the programming concepts and better thinking skills. Logo was developed in 1997 by a team from MIT. It enables you to draw various geometrical figures, such as squares, triangles and circles. You can also draw different designs based on figures, such as square and triangle. Using Logo you can also perform basic arithmetic operations such as addition, subtraction, etc. The triangular shaped cursor on the screen is called TURTLE.  Output Device
The output devices are peripherals that receive machine understandable output in the form of binary code from the processor and convert it into user understandable form. The following are the output devices:
 Monitor
As we have already studied in the previous classes that "a device, on which images are generated by the computer's video adapter is known as monitor". Here the monitor is connected by the video adaptor by a cable. Basically monitor contains two types of screen, color screen and monochromic screen. Monitor that generally displays 256 colors from a selections of 256,000 choices are called color screen whereas the monitor which displays only a single color is known as monochrome which display any multimedia object or text graphics in a single color usually black, white, green or amber. (See Figure 6.1.10)
Display devices
A number of display devices are available, which generally vary from one to the other on the basis of several key factors, may be their physical design or a display technology.
 These display devices are commonly categorized as:
Liquid Crystal Display
The LCD (Liquid Crystal Display) is one of the devices which is generally used for numerical indicators, such as in digital watches, calculators and in many others. Basically these types of display devices are very useful in those devices which are battery powered devices because they require a very small amount of current. Now a day, LCD display is widely used for the text and graphics output after some modifications.
Cathode Ray Tube
The CRT is a display device which is used in mostly television and computer display screen. Generally the CRT (Cathode Ray Tube) refers technically to an electronic vacuum tube applying beam of electrons.
Thin Film Transistor
The TFT (Thin Film Transistor) is one of the popular technologies in the field of electronics now a day. Many companies have adopted this technology to enhance the color screen. This technology is also known as Active Matrix.
Printer
Printer is one of the primaries output devices which are used to create a hard copy of any of the soft copy weather it may be a text or any picture. Generally it is one of the useful and convenient methods for delivering information using printed character. Printer s classified into two categories. (See Figure 6.1.11)
Impact Printer
Impact printers are those printers more...  Input Device
Input devices are peripherals which are used to give instructions to computer.
 The following are the various types of input devices:
 Mouse
Mouse is a type of input device which basically contains two buttons one on right and another on the left. Using these buttons you can drag any folder or document from one to the other folder. You can also control the movement of the cursor using mouse. Scrolling wheel has been introduces in some of the mouse which helps in scrolling the long document. The/allowing types of mouse are available in the market:
Mechanical mouse
Basically it contains a metal or a rubber ball in its base side, which generally rolls in any direction. The sensor which is inbuilt is a mechanical sensor which detects the direction of the rolling ball and workout on the movement of the screen pointer accordingly.
USB mouse
It has USB a (Universal Serial Bus) connector which requires a free USB port, if there is no free USB port then it is unable to perform any task on the system.
Optical mechanical mouse
The Optomechanical mouse works same as a mechanical mouse with a little change, Opt mechanical mouse the sensor used is different from the mechanical mouse, and here the optical sensor is used to detect the movements of the ball. Optical mouse
Optical mouse
Optical much advanced comparison to the other mouse. It responds very fast and precisely than any other mouse. In Optical' mouse the beams which are used to detect the movement of the mouse pointer are the laser beams. (See Figure 6.1.5)
Cordless mouse
The name itself refers its features. Basically it is not connected physically to the system. Instead it works through infrared or radio waves to communicate with the computer and utilizes batteries for its power supply. Generally it is costlier than the other serial mouse.
Joystick
Joystick is a type of the pointing device which enables user to move an object on the screen in any of the four directions, basically it is known as paddle. It is having spherical ball at both the ends. The upper ball is handled by the user and the lower spherical ball moves in a socket. Joystick is mainly used in CAD (Computer Aided Designing) and in playing computer games. It's mainly used for playing Video Games. (See Figure 6.1.6)  Introducing Computer Programming
Computer programs are set of instructions that enable a computer to interact with the user, peripherals and information. These instructions are written in a language called computer programming language. The process of writing computer programs is called computer programming. While writing a program using a computer programming language, such as C, you need to follow the syntax of that language. A programming language also provides operators that enable you to perform various tasks, such as computing and manipulating values of variables, compare values of different variables of same data types and test multiple conditions.
 Developing Flowchart
Flowchart is a technique that allows you to represent computer program graphically. Using flowchart you can easily understand the logic of a program. A flowchart represents the logical and operational steps to be performed within the system for transforming the input process into output. Flowchart serves as a basis for discussion and communication between the system analysts and the programmers.
 To create a flowchart, you need to use the following symbols
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