Transcript Mastering the Internet, XHTML, and JavaScript

Mastering the Internet,
XHTML, and JavaScript
Chapter 2
Web Browsers
Outline
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Goals and Objectives
Chapter Headlines
Introduction
Finding a web page
Browser Tasks
The two browsers
Browser window structure
Internet Explorer
Netscape Communicator
Opera
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Crazy Browser
Managing web pages
Browser Cache
Plug-ins
Bookmarks
History list
Customization
Security
Wireless browsing
Summary
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Goals and Objectives
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Goals
Understand and master the use of web browsers, to make
surfing the web a more pleasant and productive experience
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Objectives
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Browser Tasks
Browser Window Structure
Microsoft Internet Explorer
Netscape Communicator
Opera and Crazy Browser
Managing browsers: cache, plug-ins, and customization
Managing surfing: bookmarks, privacy, and security
Browsers for hand-helds
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Chapter Headlines
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2.1 Introduction
 You need a web browser to view web pages
2.2 Finding a web page
 The browser uses the URL of the web page to locate its web
server computer
2.3 Browser Tasks
 Common browser tasks are viewing, navigation,
downloading files, and printing
2.4 The Two Browsers
 Internet Explorer is widely used and Netscape is second
2.5 Browser Window Structure
 All browsers have title bar, menu bar, toolbars and status bar
2.6 Internet Explorer
 Fast and versatile browser but has no tabs, filters, or skins
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Chapter Headlines
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2.7 Netscape Communicator
 Comes in two versions: 4.8 and 7.01
2.8 Opera
 Claims to be the fastest browser on earth and has skins too
2.9 Crazy Browser
 Imitates IE, but is a tabbed browser, and has popup filters
and killers
2.10 Managing Web Pages in a Browser
 Each page has URL, XHTML file, and content display
2.11 Browser Cache
 It speeds up downloading of web pages
2.12 Plug-ins
 It enables rendering of many different file types
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Chapter Headlines
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2.13 Bookmarks
 It enables rendering of many different file types
2.14 History List
 Use browser history list to trace your past navigation
experience
2.15 Customization
 Change browser colors, fonts, and other settings to suit your
use and style
2.16 Security
 HTTPS, digital keys, and certificates protect data on internet
2.17 Wireless Browsing
 Ability to Sync handhelds for mobility
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Introduction
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A web browser is a computer program that displays web page
content
The user can specify the requested web page, by typing or clicking
on a link, in a browser
Browser can, then, locate and retrieve relevant web pages from
servers
Browser window is like the window of any other computer
application
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Finding a Web-page
Type the page URL
2. Browser sends URL to DNS server which replies with IP address of
requested server
3. TCP/IP packets go to the server through routers
4. Web server, upon receiving the packets, locates the file and sends it
to your browser through routers
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Browser Tasks
The following are important browser tasks:
Viewing
Navigating
Downloading
Printing
E-mail tools
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Two Browsers
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Internet Explorer (IE) and Netscape Communicator (NC) are
two important browsers
To download IE go to http://www.microsoft.com
To download NC go to http://www.netscape.com
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Browser Window Structure
A browser window has several bars on top of the window
and one on the bottom of the window
 Title bar : displays the title of current web page
 Menu bar : contains the pull down menus
 Navigation bar : to navigate through web-pages
 Address bar : to type URL addresses
 Status bar : displays messages about the progress of
current tasks
 Display area : displays the web page content
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Browser Window Structure
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Internet Explorer
Menus:
 File
 Edit
 View
 Favorites
 Tools
 Help
Toolbars:
 Standard buttons
 Address bar (URL)
 Links toolbar
 Status bar
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Netscape Communicator
Modules:
 Navigator
 Inbox
 Newsgroups
 Composer
 Address book
 Instant
messenger
Menus:
 File
 Edit
 View
 Go
 Communicator
 Help
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Toolbars:
 Navigation toolbar
 Address bar (URL)
 Personal toolbar
 Status bar
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Netscape Communicator
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Netscape Communicator
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Opera
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Can be downloaded at http://www.opera.com
When it crashes it starts where it left off
Menus:
 File
 Edit
 View
 Navigation
 Bookmarks
 Mail
 Window
 Help
Toolbars:
 Main bar
 Navigation bar
 Address bar
 Personal toolbar
 Page bar
 Status bar
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Opera
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Crazy Browser
Menus:
 File
 Edit
 View
 Favorites
 History
 Groups
 Options
 Tools
 Tabs
Toolbars:
 Help
 Navigation bar
 Address bar
 Links bar
 Status bar
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Managing web pages
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Managing web pages deals with three aspects:
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URL
XHTML file
Display in browser
A user can save a web page URL by making it a favorite
in IE or a bookmark in NC
A user can print the web page he is viewing by using the
Print button
A user can save the web page by using Save As… option
from the File menu
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Browser Cache
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A browser cache speeds up the retrieval and display
of web pages that are being re-visited during a
session
Browsers use two types of caching schemes
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Memory cache
Disk cache
Memory cache saves web pages during its current
session
Disk cache saves web pages from its previous session
When a page is requested, the browser first checks its
memory cache and then disk cache.
Browser also checks for updates
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Plug-ins
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Plug-ins are programs that run within the browser
Plug-ins appear to be a part of the browser even
though they are separate programs
The browser informs the user whenever a plug-in is
needed for a web page
They are easy to install
Examples include:
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Adobe Acrobat Reader : to view .pdf files
Macromedia Shockwave : plays animation and sound
Macromedia Flash : to view animations
Apple Quicktime : plays text, animations, video, and sound
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Bookmarks
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A bookmark is a saved link to a web page
User can name the bookmarked links
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my bank account, my home page
Bookmarks in one browser/machine cannot be visible
in another browser/machine
Bookmark managing task include:
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E.g.
Adding
Deleting
Organizing
IE refers to bookmarks as Favorites
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History List
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History allows users to retrace their surfing steps
History can be:
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Short term
Long term
Short tem history is related to Memory cache
Long term history is related to Disk cache
CRTL + H keyboard shortcut usually displays
browser history list
Some browsers also have separate History button
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Customization
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Browsers are customizable by users to fit their
specification and style
The user can customize:
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Default options
Default web page
Fonts
Colors
Toolbars
Display of images
Java and Javascript
Style sheets
Cookies options
Configure mail and news groups server
Change the size of cache
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Security
Security is important to prevent unauthorized access to the
information passed between clients and servers
Security over the internet is ensured by using encryption and
decryption techniques
Encryption and decryption technology is implemented by using
Secure Sockets Layer (SSL) developed by Netscape
SSL is a communication protocol and uses the HTTPS protocol
Encryption systems incorporate:
 Public and Private Key
 Digital Certificate
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Wireless Browsing
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Wireless browsing is the browsing activity on miniature screens of
small electronic devices
Some examples of devices where wireless browsing is incorporated
are:
 Pocket PCs
 Hand-held PCs
 Cell phones
 PDAs
Wireless browsing can be online or offline
Offline wireless browsing is called sync for short, in which web
pages are downloaded on the device for viewing them later
Wireless browsing is different for reason such as screen size and
disk space and have special browsers
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Wireless Browsing
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Summary
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A web browser provides access to a web page
Browsers enable internet users to perform useful tasks
Internet Explorer and Netscape Communicator are two
major browsers
A browser window has a generic structure
Menus and Toolbars in any browser allow the user to
change settings and perform browser tasks
Browser cache speeds up the display of re-visited web pages
Plug-ins run within the browser
Browsers can be customized to suit the user style
Security is a major issue with internet communications
Wireless browsing is different from desktop browsing
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