CBSE Notes for Class 9 Foundation of Information Technology – Content Technology
On a computer, whether it is connected to the Internet or not, we are basically dealing with data and information. Generally, the two terms —data and information go hand in hand. Sometimes, they are even used in place of each other. But they are actually not the same. In this chapter, we are going to find out how they differ. We will also see how data should be stored and used by the computer and also decide the hardware and the software to be used.
Data comprises of raw facts and observations. It is just a group of numbers or alphabets or both. For example, marks obtained in a subject by your class students is the data for the examination system. The particulars of students like name, age, date of birth, father’s name, address etc. are the data fields for Student Profile System.
The processed form of data is called the information. For example, Maximum marks obtained in English or List of students in the age group of 14-16 years is the information we are deriving from the data.
ENSURING DATA ENTRY WITHOUT ERRORS
Data forms the backbone of a system as all the working and the output of the system depends on the data. So a lot of care and precautions are taken while collecting the data and giving it as input to the system. That is why, several input checks are put in the system which do not let invalid data to be entered in the system.
Some of the measures for reducing errors in input are:
- Check the authenticity of data source.
- Ensure that the data entry operator is accountable for his mistakes. This will make him more responsible towards his job.
- Put data entry checks in the software, for example, displaying error if age does not fall in the specified group or if the marks obtained are more than 100 for an examination of 100 marks.
- Run the system for a sample data.
Once the data is fed to the system, it is stored in files. The type of data decides the type of file. Files are identified by MIME type. MIME stands for Multipurpose Internet Mail Extension. This specifies the structure of the file and the structure specifies the operations we can perform on a file. Most of the operating systems attach a three letter extension to the file name. This extension is used to identify the file structure/type.
For example, .txt or .doc (text file), .mdb (MS Access Database file), .ppt (PowerPoint presentation file), .com (command file), .exe (executable file), .htm or .html (HTML web page file).
Till recent times, computers had to just convert numbers and alphabets into 0’s and l’s, store them and work on them. But nowadays, the form of data has completely changed. We find data in the form of audio, video, pictures, images and animations too. So various media forms have been grouped together with data forms and what we have now is multimedia.
Multimedia is any combination of media like text, video, audio, graphics and animation with content, delivered electronically, usually through a computer. When the timing and mode of such a delivery is controlled by the user, it is called interactive multimedia.
Uses of Multimedia
Multimedia has brought a revolution in the way data is presented, so it finds its use in many fields like:
- Website Designing: What we see on the web is mostly comprised of multimedia. To make a website more informative and interesting, multimedia is the main tool used. So making creative and intelligent use of multimedia gives you a well-designed, attractive and informative website.
- Advertisement: Designing attractive visuals and sound tracks to lure the customers is where multimedia finds its use in advertising.
- Entertainment: Video games, animation movies, special effects of video and audio in
movies are all the gifts of multimedia to the world of entertainment. –
- Education: Interactive learning, creating real life situations in the class room, AV (Audio/ Visual) presentations are all the multimedia tools that have made education more interesting and entertaining.
- Engineering: Softwares like CAD, CAM and AV aids help in understanding the mechanism and concepts of engineering in a larger perspective.
- Medicine: Expert systems in remote areas and online doctor’s consultation has made it possible for medical help reach people in any corner of the earth.
- Business: Advertisements, video conferencing, presentations, designing etc. are all the fields of business and have been modernised by multimedia.
Components of Multimedia
Let us discuss in brief some of the components of multimedia.
- Audio: To store sound, we need a microphone and to hear sound, we need speakers. The microphone converts the varying air pressure which is produced when we speak in front of it, into varying voltage signals. These voltage signals are then converted to numbers and thus, stored in files with any one of the extensions — .wav, .mp3, .mpeg, .aif, .mid. The audio files are played with softwares like Windows Media Player, VLC Media player. These audio files can be used to make the presentations more effective and informative.
- Video: To input and store a moving picture, we require a webcam. The video is stored in a file which may have an extension .avi (AVI —Audio Visual Interleave format) or .mpg (MPEG —Moving Picture Expert Group). A video file mostly contains sound and picture. The softwares like Windows Media Player, VLC Media player etc. are used to view such files.
- Picture/lmages: Data may also be in the form of an image or picture. A digital picture may be taken by a webcam or any other camera. Image may be of a document scanned by scanner or made by a special software. There are many file extensions for image files, but the most popular are .jpg (or .jpeg Joint Photographic Experts Group), .gif (Graphical Interchange Format), .png (Portable Network Graphics) and .tif (Tagged Image File). In addition to these file types, many digital cameras save in a format known as .raw or a brand-specific format. A scanned file will have an extension .pdf (Portable Document File) which is accessed using Adobe Acrobat Reader. Some files which store bitmap images have .bmp extension (Bitmap Image file). The files that have clipart may have an extension .thm (Thumbnail Image File).
- Animation: Animation is the quick display of a series of images of 2-D or 3-D artwork in order to create an impression of movement. This effect is due to persistence of vision i.e., the images are moved so rapidally that we do not get to know that they are still images. Most of the cartoon movies we watch are the result of animation. Some of the animation softwares used nowadays are Animator-DV, Jumpwel, Toon Boom Animate etc.
So in this chapter, we have learnt that data not only exists in numeric and alphabetic form but in many other interesting forms like pictures, audio, visuals and even animation. In next few chapters, we will make use of such data to make our computer learning and usage more fascinating.