3rd Class

           Introduction     Inside the computer there is one program that manages all the other programs, just like a boss in an office. This program is called Windows which is the most popular operating system that controls the working of the computer. In order to start and work, every computer needs an operating system. An operating system acts like an interpreter between the computer hardware and the user. An interpreter is required because the computer and human beings speak different languages. Windows can come in different versions (such as Windows 95, Windows 98, Windows 2000 and Higher versions). Windows is a wonderful program because you can do many things with it ? play games, listen to music and paint at the same time. Let's learn how to work with Windows. You don't have to do anything special to start Windows. more...

          What is Operating System (OS)        OS means operating system of a computer. The operating system is the most important software on your computer as it controls and coordinates all the activities of a computer. It is the operating system that supports all the software on a computer. Operating system is a set of commands and programs in combination which serves two purposes. Firstly, it helps us to interact with the computer. Secondly, it helps the hardware and the software resources to communicate with each other. Basically, an OS forms a link between the three: User, Hardware and Software. It is also known as system software. It helps in operating the system in all aspects.           Window XP, more...

        Social and Ethical Behaviour     Just as it is not proper to read the letters of others and use their things without permission, accessing the personal information of others on the computer also violates ethical principles. Computer Ethics is a set of moral principles that govern an individual or a group on what is acceptable behaviours while using a computer.         Some of the rules that the students should follow while using computers are the following:  

• Do not use the computer to harm other users.
• Do not use computers to steal other's information.
• Do not access files without the permission of the owner.
• Do not copy copyrighted software without the author's permission.
• Always respect copyright laws and policies. Buy only licensed legal software from the vendors.
• Respect all more...

        Introduction   Computers and software are a part of our life, both at home and in school. The use of computers for long hours is a major issue of computer-related health risks which include repetitive stress injuries, eyestrain, obesity, back problems, etc. Correct postures pay off in later life and will help to minimize potential problems. Computers can also cause social isolation and in some cases long-term damage to physical, emotional or intellectual development and this requires a right moral behavior about which we will discuss later in this chapter.      

        Correct Postures While Using Computers     Effective Ergonomics (The science concerned with designing safe and comfortable machines for humans.) can keep our bodies healthy and pain-free when using the computer for a long period of time. Correct postures play a large role hence we should follow the good habits when we use the computer.       Do's and Don'ts Some of the computer's Do's and Don'ts are the following:  

• We should sit up straight in front of the computer. Improper sitting may result in back ache and eye sight problems.
• Make sure that your fingers are relaxed while typing and using a mouse. Use a gentle touch on the keyboard instead of pounding the keys more...

      Data Measurement System     Suppose you are asked where you live or the name of your friends, you will reply immediately because you remember them and this information is already in your memory. A computer also has a memory which stores a lot of information inside: it. A computer stores everything in its CPU.         All the data that enters into the computers first converts into the binary number system. One digit in binary number system is called bit and combination of eight bits is called byte. Bit is the smallest measuring unit of computer memory. It means binary digits. Just like we use kilograms and grams to measure weight, the computer's memory is organized as a collection of bytes. A byte is the basic unit that is used to more...

       What is Directory?       Directories are like the drawers of a table. Files are like the actual things that we keep in the drawers. A directory is also known as a folder. A folder is used to put similar files together. For example, files containing drawings can be put into the Drawing folder; files containing text can be put into the Text folder. Different types of folders are made so that various types of files can be stored in them in an organized manner. We can create folders within a folder. These are called sub- folders. Therefore, a directory allows you to group your files in a meaningful way.  A directory is a logical area on the hard disk or floppy disk where files are kept. Each directory is used to keep one type of file.     more...

          What is a File?     Imagine that you have only one notebook for doing homework and class work for all subjects. If you wish to study English notes, you will have to check the whole notebook page-by-page to find what you need. But if you make separate notebooks for class work and homework and separate notebooks for different subjects this job will become very easy. All work that we do on a computer is stored on it in the form of files. A computer file is a block of information or a resource for storing information. Computer files can be compared to paper documents which are traditionally kept in offices and libraries. Each file has a file name and can have anything including a drawing, text, picture, etc. in it. In modern computer systems, files are typically accessed using more...

        Introduction       Suppose you have only one room in your house, it would be inconvenient to study, work, cook, sleep, eat and relax, all in the same place. It will be very difficult for you to trace the things which you want and work peacefully. However, a house Ms divided into different rooms such as living room, dining room and study loom, etc. with each room containing the required things so that it is comfortable for you to live there. (See figure 3.6.1) "The same concept applies to data storage in computers as well. Just as a house contains many things like people, furniture, pets, etc, a computer also contains different types of information such as text, drawings, programs, games, etc. In a computer, we use the files and directories to keep our information in a safe and logical more...

       Input /Output Devices     In computing Input / Output or I/O refers to the communication between an information processing system (such as a computer) and the outside world. Inputs are the signals or data sent to the system and outputs are the signals or data sent by the system to the outside. Input/ Output devices are hardware devices that accept inputted information and also have the capability of outputting that information. Good examples of an Input/ Output device are a floppy diskette drive, CD-ROM and DVD-ROM units and a hard while some devices are considered only Input or Output devices, the typical devices for communication between computers are considered to be both Input and Output. For instance, the modem lets you connect to another computer, while allowing you to send and receive data and information at the same time. Another typical more...