Download Laboratory work № 4

Laboratory work № 4
LEARN INTERNET EXPLORER WEB BROWSER
ANNOTATION
Practical acquaintance with graphical user interface (GUI) and possibilities
of the Microsoft Internet Explorer (IE) software. Browsing of a Web Sites in the
Internet.
LEARNING MATERIALS
Global characteristics of the Internet
The Internet is a global system of interconnected computer networks that
interchange data by packet switching using the standardized Internet Protocol Suite
(TCP/IP – Transmission Control Protocol / Internet Protocol). The Internet is a
"network of networks". It consists of millions of private ,public, academic,
business and government networks of local to global scope that are linked by
copper wires, fiber-optic cables, wireless connections, and other technologies.
The Internet was developed on base of the ARPANET network, that has
been deployed by Advanced Research Projects Agency (known as ARPA) on
1969. In 1983 the TCP/IP (stack of protocols) becomes in-use on majority of the
key computers of the ARPANET, boosting development of the Internet.
In computing, a protocol is a convention standard that controls or enables the
connection, communication, and data transfer between interacting endpoints. In its
simplest form, a protocol can be defined as the rules governing the syntax,
semantics, and synchronization of communication. Protocols may be implemented
by hardware, software, or a combination of the two.
There are four layers in the TCP/IP stack architecture: link layer, internet
layer, transport layer and application layer. The layers near the top are logically
closer to the user application, while those near the bottom are logically closer to
the physical transmission of the data. Internet protocols defined in the set of
documents called RFC (Requests for Comments). RFC documents are enumerated.
For example, RFC 793 describes the TCP protocol (the transport layer).
The Link Layer is the networking scope of the local network connection to
which a host is attached. This is the lowest component layer of the Internet
protocols, as TCP/IP is designed to be hardware independent.
As originally defined, the Internet layer (or Network Layer) solves the
problem of getting packets from the source network to the destination network.
This generally involves routing the packet across a network of networks, known as
an internetwork or internet (lower case).
The Transport Layer's responsibilities include end-to-end message (between
interacting processes) transfer capabilities independent of the underlying network,
along with error control, fragmentation and flow control.
The Application Layer refers to the higher-level protocols used by most
applications for network communication. Examples of application layer protocols
include the File Transfer Protocol (FTP) and the Simple Mail Transfer
Protocol (SMTP). Data coded according to application layer protocols are
then encapsulated into one or (occasionally) more transport layer protocols (such
as the TCP or UDP (User Datagram Protocol)), which in turn use lower layer
protocols to effect actual data transfer. There are traditional services in the Internet:
file transfer, e-mail, remote terminal emulation. At present time the Internet
infrastructure provides many other application services in addition to traditional
ones, the most popular of them are: WWW, interactive conferences, news groups,
video on demand, electronic payments, IP-telephony, etc.
World Wide Web service of the Internet
World-Wide Web (also commonly abbreviated as "the Web", WWW or W3)
is the world's most powerful networked information system. It was originally
conceived and developed at CERN (European Center Nuclear Research), where
large high-energy physics collaborations created a demand for instantaneous
information sharing between physicists working in different universities and
institutes all over the world. Using concepts from earlier hypertext systems, the
WWW was begun in 1992 by the English physicist Tim Berners-Lee, now the
Director of the World Wide Web Consortium, and Robert Cailliau, a Belgian
computer scientist, while both working at CERN in Geneva, Switzerland. In 1990,
they proposed building a "web of nodes" storing "hypertext pages" viewed by
"browsers" on a network and released that web in 1992. Now WWW has millions
of academic and commercial users.
The terms Internet and World Wide Web are often used in every-day speech
without much distinction. However, the Internet and the World Wide Web are not
one and the same. The Internet is a global data communications system. It is a
hardware and software infrastructure that provides connectivity between
computers. In contrast, the Web is one of the services communicated via the
Internet. It is a collection of interconnected documents, graphics, multimedia
objects and other resources, linked by hyperlinks.
The WWW are based on a set of protocols and agreements that have been
implemented in proper software and allowing access to information over the
Internet. The main concept of WWW is network distribution of information
resources. This approach uses not hierarchy web links between documents via a
universal resource locator URL (Uniform Resource Locator), which completely
specifies where an identified resource is available on the Internet and the
mechanism for retrieving it.
The hypertext WWW services allow any user to add new information, search
and view it easily. That’s why the Internet gained popularity in various fields of
human activity (education, science, business, politics, etc.).
The WWW service is based on using of the Web servers. The term web
server can mean one of two things:
1.
2.
A computer program that is responsible for accepting HTTP requests
from web clients (user agents such as web browsers), and serving them
HTTP responses along with optional data contents, which usually are
web pages such as HTMLdocuments and linked objects (images, etc.).
A computer that runs a computer program as described above.
The term web client can mean one of two things:
1.
A computer program that is responsible for generating HTTP requests,
sending it to web servers and handling responses.
2.
A computer that runs a computer program as described above.
The most commonly used (but not the only one) type of Web client is the
Web browser. A Web browser is a software application which enables a user to
display and interact with text, images, videos, music, games and other information
typically located on a Web page at a Web site on the World Wide Web or a local
area network. Text and images on a Web page can contain hyperlinks to other Web
pages at the same or different Web site. Web browsers allow a user to quickly and
easily access information provided on many Web pages at many Web sites by
traversing these links. Web browsers format HTML information for display, so the
appearance of a Web page may differ between browsers.
Viewing a Web page on the World Wide Web normally begins either by
typing the URL of the page into a Web browser, or by following a hyperlink to that
page or resource. The browser then requests the resource by sending
an HTTP request to the Web server at that particular address. In the case of a
typical Web page, the HTML text of the page is requested first
and parsed immediately by the Web browser, which will then make additional
requests for images and any other files that form a part of the page. Having
received the required files from the Web server, the browser then renders the page
onto the screen as specified by its HTML, or other Web languages. Any images
and other resources are incorporated to produce the on-screen Web page that the
user sees. Most Web pages will themselves contain hyperlinks to other related
pages and perhaps to downloads, source documents, definitions and other Web
resources
The additional functionality of Web browser includes creating user-friendly
interface, providing necessary means of navigation in Web and appropriate level of
security to protect computer resources from malware and hacker attacks.
The HTML file is special text file that contains text and formatting directives
(called “tags”) of Hyper Text Markup Language (HTML). To distinguish tags from
text information the tag bracketing syntax is used in HTML language. For
example: <CENTER>, </ CENTER>.
Browsers receiving HTML-file under commands of HTML language make
formatting of interpret text reflect Hypertext information graphics sound video.
E.g. text HTML-file which will uploaded between specific above commands
browser show at center line of region viewing. In Annex 1 reproduced HTML-file
simple Web-page that reflected in viewing area browser windows fig. 4.1.
Hypertext (Hypertext) - this document is organized using the relations
between the key elements that allow access to your information in any sequence.
This information can be placed in one or in various documents that may be on the
same or different computers on the network.
Data exchange between Web-browser and Web-server is using hypertext
transfer protocol HTTP (Hyper Text Transfer Protocol). This application-level
protocol of TCP/IP family, which provides WWW service on the Internet.
Addition of HTTP browsers may support other application protocols. This,
for example, the following protocols: FTP, Telnet, Gopher, WAIS, Mailto, News
and others. They should be used, depending on which object the user will ask for
the Internet. For example, to copy files from FTP-servers to the Internet user can
use the protocol FTP. To send e-mail can use SMTP.
Versions of Web-browsers
Now there are a many count of server and client software for WWW, many
of which are distributed free. Among its are browsers that work with ASCII strings
or browsers that support graphical user interface. Today the most famous and
popular visual media browsers: Microsoft Internet Explorer and Mozilla Firefox.
Browser Internet Explorer is part of the network operating systems (OS) Windows.
Currently developed and uses the next browser versions of Microsoft Internet
Explorer: old versions of Internet Explorer: from v.2 to v.5, new browser versions:
from Internet Explorer 6 to IE 8 (with multi-tabs window, etc.).
There are versions of the above browsers, Microsoft Internet Explorer with
russian and ukrainian interface.
Characteristics of Internet Explorer 6
Version of the browser Microsoft Internet Explorer 6 has a functionality of
previous versions and, in addition, has some peculiarities. Here are the basic
functional features of the browser Microsoft Internet Explorer 6:
1.
Improved performance of Web-site review by caching mode while
downloading sites in new windows and possible disabling multimedia content
loading.
2. Support audio and video formats.
3. Support several different character encodings of Web-pages.
4. High level of security and privacy through the use of authentication
technologies, digital signature technology and PCT (Private Communication
Technology).
5. In-build mail client MS Internet Mail and Internet News client.
6. Support for object-oriented programming language Java.
7. Support for Scripting Languages VB Script (Visual Basic Script) and Java
Script.
8. Support for frames - the opportunity to share the view on independent
dynamic and static parts.
9. Using technology ActiveX, which enhances the browser. For example, the
browser Internet Explorer you can open files, Microsoft Office, image formats
GIF, JPEG and play video and sound recording format.
Graphic interface of the Internet Explorer 6
The controls of the Internet Explorer 6 conform to the window interface
standards of MS Windows. Browser window consists of the following elements:
Title bar, Menu, Toolbar, Address bar, View-section, Status bar (see Fig. 4.1). You
can delete or modify some of these windows using the "View" menu commands.
Figure 4.1 - The window of Internet Explorer.
All of actions in a browser may be induced by using menu commands or
buttons on the toolbar. The English version of the Internet Explorer main Menu has
the following command:
"File" - to work with files (open, save, print, etc);
“Edit” - for the text processing (select, delete, copy, etc);
"View" - for removal or changes to the browser window (menu,
toolbar, font), and view HTML-source of loaded file;
"Favorites" - to work with the favorite pages (add, delete, open);
“Service” - configuration settings of the browser program
(connections, multimedia, security, etc);
"Help" - to obtain information about the program and the textbook on
Web.
Toolbar Browser has buttons through which the navigation information on
the Internet:
"Back" - to go to the previous Web-page;
"Forward" - to go to the next Web-page;
"Stop" - to stop loading the current Web-page;
“Refresh” - to refresh the current Web-page;
"Home" - to download the home Web-page;
"Search" - to search on the Internet search engine;
"Favorites" - to see a list of favorite Web-pages on the browser
toolbar;
"History" - to see hitstory-log on the browser toolbar;
"Mail" - to send or receive mail throw Internet mail server;
"Print" - for printing on the printer the current Web-page.
Every Web-page is in its Internet address. To access Web-page in a box
"Address" the address bar of your browser to enter from the keyboard of its
address (URL) and to press "Enter".
TEST QUESTIONS
1. What is the Internet?
2. What popular Internet services do you known?
3. What service is provided by the Web?
4. What is Web-server?
5. What is Web-browser?
6. What is defined by the URL?
7. What is the HTML-file?
8. What is the HTTP?
9. What is hypertext?
10. What are the principles of logical links between hypertext documents?
11. What popular multimedia Web-browsers do you know?
12. What file types can be opened by Microsoft Internet Explorer?
13. Identify the elements of the Microsoft Internet Explorer window.
14. What is the purpose of the "View" menu of your browser?
15. What is the purpose of the "Stop" button at your browser's toolbar?
16. What is the purpose of the "Refresh" button at your browser's toolbar ?
HOME WORK
1. Study the learning materials.
2. Prepare written answers to the test questions.
3. Look through the laboratory tasks.
LABORATORY TASKS
Introduction to Web browser window elements
1. Run the Internet Explorer (IE). The IE shortcut can be found on the desktop of
your computer. Also you can use MS Windows "Start" menu.
2. Find the positions of following elements of the Web browser window: Title bar,
Menu, Toolbar, Address bar, View section, Status bar.
3. Remove and restore elements of the browser window: toolbar, address bar,
status bar. In the menu you should select the "View" and vertical submenus - the
necessary commands.
4. Familiar with the Context menu of your browser. Mark commands in the
protocol. The Context menu available after pointing the mouse pointer on the view
or address bar and pressing the right mouse button.
View Web-site on the Internet
5. Open Web-site on the Internet by entering a path (URL) to Web-pages on the
Web-server: http://www.onat.edu.ua/lab/hello.html. To do this in the "Address"
(Address) toolbar using keyboard to type the above URL and press "Enter".
Another technology is opening the site. Select the "File" ( "File") in the menu, and
vertical sub-menu - click "Open" (Open). In the dialog that opens, enter the URL
and click OK. As a result, the browser downloads and shows Web-page (see Fig.
4.1).
View Source HTML-File
6. Open
source-code
of
HTML-file
the
above
Web-page.
In the menu, you should select the "View" and vertical sub-menu "View HTMLcode" or "Source" (Source).
7. Another way for open source-code of HTML-file - using the context menu.
To bring the mouse pointer on the view, click the right mouse button and choose
from the menu command "View HTML-code”.
8. Compare the text of the original HTML-file with text that is displayed in the
viewing
window
of
Web-browser.
Make
conclusions.
Note commands (tags) of HTML on the HTML-file. With this tags Web-browser
displays text, images and html links. Listing from the original HTML-text file
hello.html presented in Appendix 1.
9. Close the original HTML-file.
Copy the Web-Pages
10.
Copy
active
open
Web-page
in
the
"Labor"
folder.
In the horizontal menu, you should select the "File", and submenus - "Save as ...".
In the dialog box that appears, select or create a new folder, enter the name of
HTML-file and click "Save."
11. Copy a text file of the text displayed in the viewing window of Webbrowser. To do this using the left mouse button for select the object (text, picture),
but with the right button - choose from the context menu “Copy” command. Open
any created by you text file. Copied to the clipboard item to paste the text of the
file. Close Web-browser and a text file.
View saved Web-Pages
12. Open the "Labor" folder with saved HTML-file.
13. Fix in the protocol Web-browser window and the text displayed in the view
section.
Editing saved HTML-file
14.
Open
source-code
of
stored
HTML-page
file.
15. Change the font size of text lines displayed by your browser.
This find command language HTML, which sets the browser font size line of text,
for example, <FONT SIZE=+0> and change this size, like this <FONT SIZE=10>.
Indicate
the
changes
in
the
protocol.
16. Close HTML-code file, saving the changes.
17. The "Refresh" Web-page. Note changes in the text area.
18. Close Web-browser.
19. Delete the folder "Labor" with saved HTML-file. Caution! Be careful not to
exclude another.
CONTENT OF THE PROTOCOL
1.
2.
3.
4.
Subject and purpose of laboratory work.
Your homework (short written answers to the test questions).
Results of the laboratory tasks (§ 4, 13, 15).
Conclusions.