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CLASS X NOTES, WEB APPLICATION(BASIC), CHAPTER-2, , Working with accessibility option, Computer Accessibility refers to the user friendliness of a computer system for all,, regardless of their disability. this is mainly a software issue. However, when a combination, of hardware and software, it enables a person with a disability or impairment to use a, computer. it is known as Assistive technology., There are numerous types of impairment that impact computer usage. these include:, • Cognitive impairments, and learning disabilities, such as, dyslexia,, attention deficit- hyperactivity disorder (ADHD) or autism., • Visual impairment such as low-vision, complete or partial blindness, and color, blindness., • Hearing impairment including deafness., • Motor or dexterity impairment such as paralysis, cerebral palsy, or carpal, tunnel syndrome, and repetitive strain injury., Launching accessibility options, To launch accessibility options in Windows XP,, Click Start > Control Panel > Accessibility options. the Accessibility Options window appears., STICKY KEY, StickyKeys is an accessibility feature to help computer users with physical disabilities,, but it is also used by others as a means to reduce repetitive strain. StickyKeys allows, the user to press and release a modifier key, such, as Shift, Ctrl, Alt, or the, Windows key, and have it remain active until any other key is pressed., , FILTER KEY, , FilterKeys is a feature of Microsoft Windows. it is an accessibility function that tells, the keyboard to ignore brief or repeated keystrokes, making typing easier for people, with hand tremors., TOGGLE KEY, ToggleKeys is also a feature of Microsoft Windows. it is an accessibility function which, is designed for people who have vision impairment or cognitive disabilities. When, toggleKeys is turned on, computer emits sound cues when the locking keys (Caps, Lock, num Lock, or Scroll Lock) are pressed. A high sound is emitted when the keys, are switched on and a low sound is emitted when they are switched off., SOUND TAB, Select the Sound tab. A window with options to configure accessibility options for sound is, displayed., SOUND SENTRY, , SoundSentry is designed to help users with auditory impairments. SoundSentry generates, visual warnings, such as a blinking title bar, or a flashing border, whenever the, computer generates a sound., , SHOW SOUND, ShowSounds instructs applications that convey information by sound, to also, provide information visually, through text captions or informative icons., DISPLAY TAB, Select the Display tab. A window with options to configure accessibility options for, display is displayed., HIGH CONTRAST
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High Contrast is an accessibility feature to assist people with vision impairment. You can, change the size and, color of fonts and the background for ease of viewing., CURSOR OPTION, Cursor Options is also an accessibility feature that assists people with vision impairment, by changing the blink rate and width of the cursor., •To change the speed of the cursor blink, move the Blink Rate slider back and forth., notice the cursor blinking at various speeds., • To change the width of the cursor, move the Width slider back and forth. notice the, with of the cursor changing., MOUSE TAB, MOUSE KEY, MouseKeys is an accessibility feature that assists people who have difficulty, using a mouse. This, option uses the keyboard (especially numeric, keypad) as a pointing device instead of a mouse., GENERAL TAB, This tab enables you to configure accessibility options for all users., SERIAL KEY, SerialKeys, is an accessibility feature that assists people that have difficulty, using a keyboard, or a mouse (or both). they can use special devices such as Sip,, Puff and Breath Switches to provide input to the computer through Serial Ports., For example, sipping on the tube activates one device, while puffing on the same, tube activates another., , NETWORKING FUNDAMENTAL, COMPUTER NETWORK, A computer network is a collection of computers and other hardware components, interconnected by communication channels (cables or satellites) that allow sharing of, resources and information. this session introduces you to the basic fundamental concepts, of networking and internet and using different types of internet connection., NETWORK ARCHITEACTURE: There are two type of computer architecture that is, 1. Peer-to-Peer (P2P)architecture, Networks in which all computers have an equal status are called peer to peer, networks. Generally in such a network each terminal has an equally competent CPU., 2. Client Server Architecture, Networks in which certain computers have special dedicated tasks, providing, services to other computers (in the network) are called client server networks. the, computer(s) which provide services are called servers and the ones that use these, services are called clients., , Types of Computer Network, There are two major types of network Local Area network (LAN) and Wide Area network, (WAN)., LOCAL AREA NETWORK(LAN)
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A local area network (LAN) is one which connects computers and devices in a limited, geographical area, such as home, school, computer laboratory, office building, or closely, positioned group of buildings., Usually local area networks offer very high speeds and are used for connecting computers and, peripherals such as printers, scanners, etc., , WIDE AREA NETWORK(WAN), A wide area network (WAN) is one which covers a broad area (i.e., any network that links, across metropolitan, regional, or national boundaries). the internet is the most popular, WAN, and is used by, businesses, governments, non-profit organizations, individual, consumers, artists, entertainers, and many others., , PAN(Personal Area Network), •, •, , Personal Area Network is a network arranged within an individual person, typically, within a range of 10 meters., Personal Area Network is used for connecting the computer devices of personal use is, known as Personal Area Network., , MAN(Metropolitan Area Network), •, •, •, , A metropolitan area network is a network that covers a larger geographic area by, interconnecting a different LAN to form a larger network., Government agencies use MAN to connect to the citizens and private industries., In MAN, various LANs are connected to each other through a telephone exchange line., , Internet, ➢ The internet is a global system of interconnected computer networks that, use the standard internet protocol suite to serve billions of users worldwide., it is a network of networks that consists of millions of private, public,, academic, business, and government networks., ➢ Internet is one of the most useful technologies of modern times which help, us in our daily, personal and professional life. internet is widely used by, students, educational institutes; scientist and professionals to gather, information for research and general information., , World Wide Web(www), , ➢ World Wide Web (abbreviated as WWW or W3, commonly known as the Web), is, a system of interlinked hypertext documents accessed via the internet. With a web, browser, one can view web pages that may contain text, images, videos, and other, multimedia, and navigate between them via hyperlinks., ➢, , A Web Browser is a software used to view Web sites and acts as an interface between the user, and the World Wide Web. A Web server is a computer that, stores web sites and, their, related files for viewing on the Internet., , Some of the advantages associated with networking are:, Data Sharing: One of the most important uses of networking is to allow the sharing of data., Users can, send text files, spread sheets, documents, presentations, audio files,, video files etc. to other users., , •, , •, , Hardware Sharing: Hardware components such as printers, scanners, etc. can also be, shared. For example, instead of purchasing 10 printers for each user, one printer, can be purchased and shared among multiple users thus saving cost., , • Internet Access Sharing: You can purchase a single internet connection and share it among, other computers in a network instead of purchasing multiple internet connection for each
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computer. this is very commonly found in internet café (browsing centres), schools, colleges,, companies, etc., , •Usage of network based applications: Such as web browsers, email clients, chat application,, audio & video calling, etc is another advantage., , Internet service provider, An Internet service provider(ISP) is an organization which provides you with access to, the, Internet via a dial-up (using modem) or direct (hard wired) or wireless connection. Choosing, connectivity depends on the availability of a particular technology, speed and connection type in, your area., , MODEM, Á modem is a device that converts digital computer signals into a form (analog signals), that can travel over phone lines. it also re-converts the analog signals back into digital, signals. the word modem is derived from its function MOdulator/DEModulator., , Types of common internet connectivity, There are different types of Internet Connectivity available today; it can be widely categorized into, wired and wireless access. Following table is a summary of different types of internet connectivity, categorized into wired and wireless:, , Dial-up: Dial-up internet access is a form of internet access that uses the facilities of the public, switched telephone network (PStn) to establish a connection to an internet service provider (iSP) via, telephone lines using a device called MODEM. Users dial a particular number provided by the iSP, and gain access to the internet., DSL: Digital subscriber line(DSL) provide internet access by transmitting digital data over wires of, a local telephone network. DSL service is delivered along with wired telephone service on the same, telephone line. On the customer premises, a DSL filter removes the high frequency interference,, enabling simultaneous use of the telephone and data transmission. For using a DSL connection, you, need a DSL modem and a subscription, Cable internet Access: Cable internet Access is a form of broadband internet access that uses the, cable television infrastructure. Cable internet Access is provided through existing cable tV networks;, this is similar to DSL that is provided over existing telephone lines., , 3g: 3G,, , short for 3rd Generation is a set of standards used for mobile devices and mobile, telecommunication services and networks. High-Speed Downlink Packet Access (HSDPA) is 3G, mobile telephony communications protocol that allows higher data transfer speeds and capacity. if, support for 3G is available on your mobile phone, you can subscribe to the 3G connectivity with, your iSP in order to get high speed internet connection on your phone., , WimAx:, , WiMAX (Worldwide interoperability for Microwave Access) is a wireless, communications standard designed to provide mobile broadband connectivity across cities and
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countries through a variety of devices. WiMAX is a long range system, covering many kilometres, and is typically used where DSL or Cable Internet Access cannot be used; this could be difficulty, in laying out cables for home or offices located in remote locations but need access to the, Internet., , Wi-Fi: Wi-Fi is a popular technology that allows an electronic device such as computers or mobile, phones to exchange data wirelessly over a network, including high-speed internet connections. WiFi devices such as personal computer, smartphones, video game console, etc. can connect to a, network resource such as internet through a device called the Wireless Access Point (WAP). WiFi is, used where cables cannot be run (such as old buildings, outdoor areas) to provide network and, internet access. Wi-Fi can also be used where users require mobile connectivity., , Data transfer on the internet, In very simple language, let’s see what happens to a piece of data, say a Web page, when it is, transferred over the internet:, o The data is broken up into bits of same sized pieces called packets., o A header is added to each packet explaining where the data has come from,, where it should end up and, where it fits inwith the rest of the packets., o Each packet is sent from computer to computer until it finds its destination., Each computer on the way decides where next to send the packet. All packets, may not take the same route., o At the destination, the packets are examined. if any packets are missing or, damaged, a message is sent asking for them to be re-sent. this continues until all, packets have been received intact., o The, packets are, now, reassembled into their original form. All this, done in seconds!, , Introduction to instant messaging, Instant messaging (IM) is a form of communication over the internet that offers an instantaneous, transmission of text-based messages from sender to receiver. Most instant messaging software, include the option for performing file transfers, audio chat, video calling and conferencing,, sharing desktops, etc. apart from standard text chat. instant messaging software is widely used for, personal and commercial use., Unlike email, instant messaging happens in real-time and the response from participants can be, spontaneous. Some instant messaging software allows users to view messages received when they, are not logged on. These are called “Offline Messages”., , Key Features of an instant messaging are as follows:, •, •, •, •, •, , Text Messages can be sent to one, or, more person (Similar to, SMS), Audio calling and conferencing., Video calling and conferencing., File transfers (Not limited to documents, spread sheets, audio files, video files, etc.), Message history (Save messages for future reference)., , Instant messaging account, Participants messaging to each other need to be signed in to the same instant messaging software., to use instant messaging software, a user must have a valid instant messaging account., instant messaging accounts differ in formats; some instant messaging software such as Yahoo!, Messenger, Windows Live Messenger use email addresses for managing the account and software, such as Skype use standard names., , Instant messaging Service
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There are two kinds of instant messaging software – application based and Web based., 1.Application based instant messaging software is downloaded and installed on, users computer. Some of the popular instant messaging software are:, Google Talk,Yahoo!Messenger ,Skype, Windows LiveMessenger,Rediff Bol,etc., , 2.Web based instant messaging software is accessed using browsers such as Internet, Explorer, Mozilla Firefox, Google Chrome, etc. Some of the popular web based instant, messaging software are: Meebo ,Yahoo! Messenger for the Web ,MSN Web Messenger, IMO,, etc., , Creating an instant messaging account, ➢ Google talk is an instant messaging service that provides both text and voice, communication developed by Google inc. Google talk can also be used for making, video calls and to view updates from GMAiL mailbox., ➢ Google talk is free and is available as application based (users need to download, and install Google talk application to their desktops, mobiles or laptops) and web, based (users can use Google talk through a browser after signing into their Gmail, account)., , Launching google Talk, • To, launch Google Talk, Click Start > Programs >google Talk>google Talk., To use Google talk, you need to sign in with your account details., , Chatting with a contact-Google talk, Whenever your friend in the contact list is online you can see the person along with a green dot, You canstart sending text chat message instantly by double-clicking on a contact. A window will, pop up as displayed in the figure below. You can type the text in the text box and press enter;, the other person will see the text message and respond to your message., • Go ahead and get the contacts of a couple of your classmates and, chat, with, them., , There are some general rules and etiquettes to be followed while chatting. they are, almost the same as those that apply for emails., ➢ Messages should be short and to the point., Always introduce yourself by name if your screen name doesn’t reflect it., Always ask if the other person has time to chat first - regardless of how important, you, thinkwhat you have to say is, it’s not going to be well received if the recipient is busy., ➢ In a business environment, know exactly what you want to discuss., ➢ Typing your messages in uppercase is extremely rude - it’s considered shouting and very, aggressive., ➢ Give people time to respond- Multiple questions sent to a recipient before they’ve had, a chance to answer can seem more like an interrogation rather than a conversation., ➢ Wherever possible, give the person you are communicating with your undivided attention., It’s not just a sign of respect, but if you have multiple conversations happening or are allowing, other issues to distract you, you may miss an important point in the other person’s messages, ➢, ➢, , or lose the gist of the conversation., ➢ It’s important to properly end an IM conversation - you may think the chat is, over, but the other person may not. While you’re off doing other things, they may, be sitting there staring at the screen waiting for further communication from you!!, , Creating and publishing website –BLOG
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A blog is a discussion style site used by non-technical (or technical users) users for creating, personal web pages. Blogs are similar to an online personal diary and simple to use., You can use a blog to convey messages about events, announcements, news, reviews, etc. Blogs are, usually managed using a web browser and this requires active internet connection. You can also, use, offline blog, software, to, create content first, and, later, publish the content when an active internet connection is available., , There are hundreds of websites that offer blog service for free. Some of the popular, blogs include: www.WordPress.com, www.blogger.com, www.blog.com,, www.weebly.com,www.blogsome.com, , Creating a blog account, WordPress is free web service that you can use to create a beautiful website or blog. WordPress has, support for “themes” for customizing the design of a blog. Themes can make the blog, or the webpage look attractive., , Before you start using a blog, a blog account is required., To create one, you need a web browser and an internet connection. Then sign up the, wordpress.com website Next enter blog address and provide username and password. then give, email id and then select your language and click OK., , USING OFFLINE BLOG EDITOR, if you do not have an active internet connection, you can create blogs using a blog application and, publish the blog whenever internet connectivity is available., There are several free offline blog editors available that can be downloaded and installed on the local, computer such as: Qumana,Windows,Live,Writer,Blogdesk., , Launching Qumana, To launch Qumana, Click Start > Programs > Qumana > Qumana., You can also Double-click on the Qumana icon on the desktop if available, , ONLINE TRANSACTION, Online shopping is a form of electronic commerce where customers can buy or sell goods over the, internet. Customers need to have an active internet connection for viewing goods or services offered, by a seller; customers can pay online using a credit, debit card or by internet banking., , Online shopping could be useful in situations when:, ➢ A customer does not have sufficient time to visit stores., ➢ Visiting a store is more expensive than purchasing a product online., ➢ A product or service that is not available in the local market is available online., Some of the popular online transaction websites are:, ➢ IRCTC, an online portal for booking flight and traintickets., ➢ EBay, an online portal for buying and selling goods., ➢ Redbus, an online portal for booking bus tickets., INTERNET SECURITY, Explain the purpose of internet security., Internet security is a branch of computer security specifically related to the, Internet,, often involving browser security but also network security. its objective is to establish, rules and measures to use against attacks over the internet. the internet represents an, insecure channel for exchanging information leading to a high risk of intrusion or fraud,, such as phishing., , Different kinds of online threats
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Online threats such as Phishing email spoofing, chat spoofing, etc. Can increase the, chances of users getting compromised., Phishing: Phishing is the fraudulent attempt to obtain sensitive information or data,such, as usernames,passwords and credit card details, by disguising oneself as a trustworthy, entity in an electronic communication., Email Spoofing: Email Spoofing is the creation of email messages with a forged sender, address., Chat Spoofing: Chat spoofing is a one in which when a computer system or a user of a, computer masquerades (masquerades means false) to be another identity while engaging, in chat., , Difference between webpage and website., ➢, ➢, ➢, , Webpage and website are relevant but distinct words., A web page can be considered as a single entity whereas a website is a combination of, webpages., Web pages are accessed through a browser while in website HTTP,and DNS protocol are, used to access it., , Best practice for Security, Use strong passwords, a combination of alphanumeric and special characters could be used, for creating a password that is not so easy to crack or guessed by other users. Do not keep, passwords such as your favorite color, friends or relatives name, bike number, mobile, number either as single or combined option. these passwords are easy to guess if a user, knows you personally. Change your password frequently at least 2 or 3 weeks so that your, account information remains secure., , Following is a general guideline for managing strong passwords., ➢ Keep the length of the password at least 12-14 characters if permitted., ➢ Avoid keeping passwords based on repetition, dictionary words, letter or, number sequences, usernames, relative or pet names, etc., ➢ Including numbers, and symbols in passwords if allowed., ➢ Use capital and lower-case, letters., ➢ Avoid using the same password for, multiple, sites or, purposes., ➢ Avoid using something that the public or workmates know you strongly like or, dislike., ➢ Use random, password, generators, if, possible., 1.Backup your data: Always keep copies of personal data in additional media such as compact discs,, pen drives, etc. this could be helpful in situation when there is a loss of data., 2.Use encryption software: (Usually available within the operating system) to protect your data, from unauthorized users., 3.Keeping your username and password private: never save your username or password on, computers that are used in shared environments such as internet café., 4.registering with websites: Read the privacy statement or policy whenever you register with a, website, the statement or policy will include information about how the website use personal data., 5.Do not share personal information: Websites require you to fill, out forms containing, fields such as name, gender, age, email address, school, etc, 6.Secure transactions: if you are using online shopping or transactions, websites even store your, credit card or online banking personal information such as your credit card number, account details,, etc., 10.Install firewalls, 7.Use antivirus and antispyware software, 11.Never install software from, 8.Do not immediately respond to mails from unknown users, unknown sources, 9.Clear browser cookies frequently, 12.remove, unwanted, or, QUETSION, unknown software applications, Fill in the blank
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1, 2., 3., 4., 5., 6., 7., 8., 9., , The option in Microsoft Windows XP used for helping users with physical disabilities and to, reduce repetitive strain is ____________________., Sound Sentry is designed to help users with ______________________ impairments., The High Contrast option in Microsoft Windows XP is designed to assist people with, ________________ impairments., ___________________ is designed to assist people that have difficulty using a, keyboard or a mouse., The acronym for LAN is _________________., Three types of Wired internet Connectivity are ___________ , _________ & ___________., Three types of Wireless internet Connectivity are _________ , ___________ & _________., _______________ is a form of communication over the internet that offers an instantaneous, transmission of text-based messages from sender to receiver., ____________ , ____________ & _______________& Web Camera are required for audio and, video conferencing., , Answer the following, 1.What is the definition of networking?, 2.What are the advantages of networking? 3. What are the different types of networking?, 4. Explain LAN and WAN., 5 List any, five, application, based instant messaging, software., 6. What do you mean by instant messages?, 7.State any 03 rules and etiquettes to be followed while chatting on the internet., 8. What are the basic needs to use instant messaging (chat) softwares., 9. Explain the purpose of a blog., 10. List any 5 websites that provide blog service., 11. Difference between web page and website., 12. Explain, the, purpose, of, an, offline blog editor., 13., List, any, five, offline blog editors., 14. Explain the purpose of Online transactions., 15., List, any, five, websites, that, allow online transactions., 16. List any three payment tools to use online transactions., 17. Explain the purpose of internet Security., 18. Explain different kinds of online threats
