Transcript Web pages
Chapter 10: Web Basics Computing Fundamentals Chapter 10: Web Basics Learning Objectives: • Identify the components that make up the web • Use the basic functions of a web browser • Search the Internet • Understand the need for security and recognize secure connections Computing Fundamentals How the Web Works • The Internet is a global network of millions of computers that can communicate with each other • World Wide Web (WWW) A network of interconnected pages of information stored on publicly accessible servers. Computing Fundamentals Web Browsing Components • Web servers: Store and provide access to web sites • Web browsers: Request and display information to individuals • Web pages: The individual documents that web servers store and web browsers request. Computing Fundamentals Web Servers • Powerful computers that provide data or services to other computers • Receive requests for web page data and supplies it by sending it over the Internet. Computing Fundamentals Web Browsers • Many are available (Internet Explorer, Firefox, Chrome, Safari) • Most are available for multiple operating systems • Relationship between browser and server is platform-independent Computing Fundamentals Web Pages • A web page is a file that is formatted for use on WWW • Written in Hypertext Markup Language (HTML). Computing Fundamentals Web Pages • Web page contains text, graphics, audio, and video • Hyperlinks are pointer link to other pages or content in the same page • Static web page • content does not change • can be updated manually • Dynamic web page • frequently updating content • weather report Computing Fundamentals URLs • Uniform resource locator (URL) is a web page address Computing Fundamentals Parts of a URL • Protocol: set of rules for the transmission; most common is http. Another example is IP • Domain name: destination server, such as www.uob.edu.bh. • Top-level domain is the final part, example: .com, .net, .edu, and many more. • Some domain names include a two-letter country code, for example, .bh, .uk, .ae, .sa. • Subdomain: usually www, but can be others • Path: exact location on the server can include a folder (news) and a file name (story24871.htm) Computing Fundamentals IP Addresses • IPv4 • • • • • Currently used on the Internet 32 bit binary number Represented in dotted decimal notation Example, 131.107.23.100 More than 4 billion combinations • IPv6 • Will be used on the Internet in the future (already in limited use) • 128 bit binary number • Represented as eight groups of four hexadecimal numbers • Example:2001:0:0:635:7b62:12ab:342:1038 Computing Fundamentals Identifying Your IP Address Computing Fundamentals IP Address Translation • Domain Name System (DNS) servers translate between IP addresses and domain names • directory lookup that converts domain names into their corresponding IP addresses • The process is called name resolution Computing Fundamentals Browser Basics • Homepage: The page that is displayed when you first launch your web browser. • Also the main / first page of a website. • A tab enables you to have multiple web pages open at once within the same browser window Computing Fundamentals Identifying Secure Sites • https:// rather than http:// • Lock symbol in Address bar • Address bar may have a green background Computing Fundamentals Adding Favorites (Bookmarks) 1. Click the Favorites button (star) 2. Click Add to Favorites 3. Click Add Computing Fundamentals Browser History Computing Fundamentals Browser History 1. 2. 3. 4. Click Favorites (star) Click History tab Double-click a date range Click a site to revisit it Computing Fundamentals Uploading Files with FTP • Use an FTP client application, or use a browser • URL begins with ftp:// rather than http:// Computing Fundamentals Plug-Ins (Add-Ons) • Plug-in: An additional piece of software added to a web browser application to add support for a certain type of content; Microsoft calls them add-ons Computing Fundamentals Managing Add-Ons in IE • Choose Tools, Manage Add-Ons Computing Fundamentals Web Search • Search engine: a software tool used to locate information on the web • Top search engines include: • • • • • • • • • Google Bing Yahoo! Ask AOL Wow WebCrawler MyWebSearch Info Computing Fundamentals Conducting a Search • Go to the search engine website and type your keywords in the Search box there • Also, you can type search words directly into the Address bar to see results from the default search engine • Search results contain: • Title • URL • Description or excerpt Computing Fundamentals Search Results Example Computing Fundamentals Advanced Search Options Computing Fundamentals Web-Based Applications • These days, developers can use a number of programming languages to run web-based applications within a web browser. • A web-based application is software that is downloaded and run within the web browser rather than being installed directly on the user’s computer. Computing Fundamentals Search Operators • Different search engine have different syntax for advanced searches • Another way to narrow your search is to enter specific search operators in the Search field. • A search operator is a word or symbol that has a specific function when carrying out a search. Computing Fundamentals Evaluating Results Accuracy • What is the reputation of the information source? • Is the information objective and fair? What agenda does the source have? • Are outside sources cited, or is this just one opinion? • Is this information provided by a group of professionals? Amateurs? Hobbyists? • Sponsored Link A hyperlink that is placed on a page because a payment has been made. • Many web pages contain ads, and the ads are not always sectioned off separately from the main text. Computing Fundamentals Evaluating Results Accuracy • Forums are public message boards that you access via websites. They may be sponsored by a particular company or group. • A knowledge base is a set of articles provided and maintained by a company or government agency about its products. It is a more reliable source of information. • Encyclopaedia sites vary in their accuracy and reliability. • Wiki A web-based application that can be edited by anyone and that is usually informational or instructive in nature. • Examples: Wikipedia, WikiTravel. Computing Fundamentals Virtual Private Network (VPN) • A secure pipeline between a VPN-enabled web server and an individual computer • To set up in Windows, use the Network and Sharing Center. Choose Set Up a New Connection or Network, and then choose Connect to a Workplace. Computing Fundamentals Key Terms • domain name • • Domain Name • System (DNS) • • dynamic IP • address • • Favorite • • home page • • hyperlink • HyperText Transfer • Protocol (HTTP) • • • Internet • • IP address IPv4 address IPv6 address name resolution plug-in search engine search operator server static IP address tab top-level domain uniform resource locator (URL) • virtual private network (VPN) • web-based application • web browser • wiki • Wikipedia • World Wide Web (WWW) Computing Fundamentals Summary • 1 . What is the relationship between the Internet and the World Wide Web? • 2 . What does a hyperlink do? • 3 . What type of server is used to resolve domain names and URLs to IP addresses? • 4 . What browser feature enables users to open multiple web pages in a single browser window? • 5 . What function does a search engine serve? • 6 . What is a VPN?