3. It is the largest network in the world that connects hundreds of thousands of
individual networks all over the world.
The Internet is a network of computers spanning the globe. It is also called
the World Wide Web.
The popular term for the Internet is the “Information Highway”.
To access the Internet, an existing network need to pay a small registration
fee and agree to certain standards based on the TCP/IP (Transmission
Control Protocol/Internet Protocol) .
No one owns it
It has no formal management organization.
As it was originally developed by the Department of defense, this lack of
centralization made it less vulnerable to wartime or terrorist attacks.
4. Send e-mail messages.
Send (upload) or receive (down load) files between
computers.
Participate in discussion groups, such as mailing lists
and newsgroups.
Surfing the web.
5. Many schools and businesses have direct access to
the Internet using special high-speed
communication lines and equipment.
Students and employees can access through the
organization’s local area networks (LAN) or
through their own personal computers.
Another way to access the Internet is through
Internet Service Provider (ISP).
6. A commercial organization with permanent
connection to the Internet that sells temporary
connections to subscribers.
Examples:
Prodigy, America Online, Microsoft Network,
AT&T Networks.
7. To access the Internet, an existing network need to
pay a small registration fee and agree to certain
standards based on the TCP/IP (Transmission
Control Protocol/Internet Protocol) reference
model.
Each organization pays for its own networks and
its own telephone bills, but those costs usually
exist independent of the internet.
The regional Internet companies route and forward
all traffic, and the cost is still only that of a local
telephone call.
8. The Web (World Wide Web) consists of information
organized into Web pages containing text and graphic
images.
It contains hypertext links, or highlighted keywords and
images that lead to related information.
A site or area on the World Wide Web that is accessed by
its own Internet address is called a Web site.
A collection of linked Web pages that has a common
theme or focus is called a Web site.
The main page that all of the pages on a particular Web
site are organized around and link back to is called the
site’s home page.
9. Once you have your Internet connection, then you need special
software called a browser to access the Web.
Web browsers are used to connect you to remote computers,
open and transfer files, display text and images.
Browsers connect computers to the Internet, and allow people
to “surf the Web.”
Web browsers are specialized programs used to access webpage
and web server.
Examples of Web browser: Netscape Navigator (Navigator) and
Internet Explorer.
10.
11. 1. Title bar – tells you the name of the web page
2. Menu bar – has commands for moving around the webpage, printing,
etc
3. Tool bar – short cuts to commands. Each picture represents a
command
4. Address bar – webpage address. If you want to go directly to a web
page, you will need to know the address.
12. A web address is typically composed of four parts:
For example, the address http://www.google.ca is made up of
the following areas:
http://
This Web server uses Hypertext Transfer Protocol (HTTP).
This is the most common protocol on the Internet.
www
This site is on the World Wide Web.
google
The Web server and site maintainer.
ca
This tells us it is a site in Canada.
13. Endings of web pages tells us a bit about the page. Some
common endings to web addresses are:
com (commercial)
edu (educational institution)
gov (government)
net (network)
org (organization)
You might also see addresses that add a country code as the
last part of the address such as:
ca (Canada)
uk (United Kingdom)
fr (France)
us (United States of America)
au (Australia)
14. Serve the data to the requested client
A Web server is a program that uses HTTP (Hypertext
Transfer Protocol) to serve the files that form Web
pages to users, in response to their requests, which are
forwarded by their computers' HTTP clients.
15. Web is a collection of files that reside on computers,
called Web servers, that are located all over the world
and are connected to each other through the Internet.
When you use your Internet connection to become
part of the Web, your computer becomes a Web client
in a worldwide client/server network.
A Web browser is the software that you run on your
computer to make it work as a web client.
16.
17. Each computer on the internet does have a unique
identification number, called an IP (Internet Protocol)
address.
The IP addressing system currently in use on the Internet
uses a four-part number.
Each part of the address is a number ranging from 0 to
255, and each part is separated from the previous part by
period
For example: 106.29.242.17
18. Most web browsers do not use the IP address to locate Web sites
and individual pages.
They use domain name addressing.
A domain name is a unique name associated with a specific IP
address by a program that runs on an Internet host computer.
This program, which coordinates the IP addresses and domain
names for all computers attached to it, is called DNS (Domain
Name System ) software.
The host computer that runs this software is called a domain
name server.
19. The IP address and the domain name each identify a particular
computer on the Internet.
To identify a Web pages exact location, Web browsers rely on
Uniform Resource Locator (URL).
URL is a four-part addressing scheme that tells the Web browser:
What transfer protocol to use for transporting the file
The domain name of the computer on which the file resides
The pathname of the folder or directory on the computer on which the
file resides
The name of the file
21. The transfer protocol is the set of rules that the
computers use to move files from one computer to
another on the Internet.
The most common transfer protocol used on the
Internet is the Hypertext Transfer Protocol (HTTP).
Two other protocols that you can use on the Internet
are the File Transfer Protocol (FTP) and the Telnet
Protocol.
23. An HTTP session is a sequence of network request-
response transactions. An HTTP client initiates a
request by establishing a Transmission Control
Protocol (TCP) connection to a particular port on a
server.
An HTTP server listening on that port waits for a
client's request message.
24. HTTP provides multiple authentication schemes such
as Basic access authentication and Digest access
authentication which operate via a challenge-response
mechanism whereby the server identifies and issues a
challenge before serving the requested content.
25. GET:
The GET method requests a representation of the specified resource.
Requests using GET should only retrieve data and should have no
other effect.
HEAD:
The HEAD method asks for a response identical to that of a GET
request, but without the response body.
POST:
The POST method requests that the server accept the entity enclosed
in the request as a new subordinate of the web resource identified by
the URI.
26. PUT:
The PUT method requests that the enclosed entity be stored
under the supplied URI
DELETE:
The DELETE method deletes the specified resource.
TRACE:
The TRACE method echoes the received request so that a
client can see what (if any) changes or additions have been
made by intermediate servers.
OPTIONS:
The OPTIONS method returns the HTTP methods that the server
supports for the specified URL. This can be used to check the
functionality of a web server by requesting '*' instead of a
specific resource.
27. A “web page” was most likely to be a “static” page,
meaning what we saw was the result of just the HTML
code in a single file.
Modern “web pages” are dynamically generated from
data stored in a database server.
They are displayed using templating engines and other
more advanced techniques, all the while being
accentuated with liberal doses of JavaScript and CSS.
28. Web programmers use several languages to create the documents that servers
can provide to browsers.
The most basic of these is XHTML, the standard mark-up language for describing
how Web documents should be presented by browsers. Tools that can be used
without specific knowledge of XHTML are available to create XHTML
documents.
A plug-in is a program that can be integrated with a word processor to make it
possible to use the word processor to create XHTML. A filter converts a document
written in some other format to XHTML.
XML is a meta-mark-up language that provides a standard way to define new
mark-up languages.
29. JavaScript is a client-side scripting language that can be embedded in XHTML
to describe simple computations. JavaScript code is interpreted by the browser on
the client machine; it provides access to the elements of an XHTML document, as
well as the ability to change those elements dynamically.
Flash is a framework for building animation into XHTML documents. A
browser must have a Flash player plug-in to be able to display the movies
created with the Flash framework.
Ajax is an approach to building Web applications in which partial document
requests are handled asynchronously. Ajax can significantly increase the speed of
user interactions, so it is most useful for building systems that have frequent
interactions.
PHP is the server-side equivalent of JavaScript. It is an interpreted language
whose code is embedded in XHTML documents. PHP is used primarily for form
processing and database access from browsers.
30. Servlets are server-side Java programs that are used for form processing,
database access, or building dynamic documents. JSP documents, which
are translated into servlets, are an alternative approach to building these
applications.
JSF is a development framework for specifying forms and their processing
in JSP documents.
ASP.NET is a Web development framework. The code used in ASP.NET
documents, which is executed on the server, can be written in any .NET
programming language.
Ruby is a relatively recent object-oriented scripting language that is
introduced here primarily because of its use in Rails, a Web applications
framework.
32. Multipurpose Internet Mail Extensions, commonly
termed MIME, is a specification for enhancing the
capabilities of standard Internet electronic mail.
All human written emails can be transmitted
through in MIME format.
Standard email, defined over ten years ago by a
variety of documents (primarily RFC821 and RFC822)
has been showing its age for some time.
1/3/2019 32
33. MIME provides extensions, allowing some new uses of
electronic mail; messages now may have:
Multiple objects within a single message
Text with unlimited line length or overall length
Character sets other than 7-bit ASCII
Multi-font messages
Binary or application-specific files
Images, audio, video and multi-media messages
1/3/2019 33
34. Extensions to the current email
1. Non-text attachments such as images, videos,
audios and other multi-media messages.
2.Ability to send multiple objects within a single
message.
3.Character sets other than US-ASCII
4.Writing header information in non-ASCII character
sets
5.Text with unlimited length
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35. 1/3/2019 35
MIME was introduced to extend the current SMTP, or
Simple Mail Transport Protocol, in order to send
data other than ASCII characters through various
web clients and web servers.
36. RFC 2045:
RFC 822 defines a message representation protocol
specifying considerable detail about US-ASCII
message headers,
Redefines the format of messages to allow for:
Textual message bodies in character sets other than US-
ASCII
An extensible set of different formats for non-textual
message bodies
Multi-part message bodies, and
Textual header information in character sets other than
US-ASCII.
37. RFC 2046:
The five discrete top-level media types are:
Text -- textual information. The subtype "plain" in particular
indicates plain text containing no formatting commands or
directives of any sort. Plain text is intended to be displayed "as-
is". No special software is required to get the full meaning of the
text, aside from support for the indicated character set.
Image -- image data. "Image" requires a display device (such as a
graphical display, a graphics printer, or a FAX machine) to view
the information. An initial subtype is defined for the widely-used
image format JPEG. Subtypes are defined for two widely-used
image formats, jpeg and gif.
Audio -- audio data. "Audio" requires an audio output device
(such as a speaker or a telephone) to "display" the contents.
38. video -- video data. "Video" requires the capability to
display moving images, typically including specialized
hardware and software.
Application -- some other kind of data, typically either
uninterpreted binary data or information to be
processed by an application. The subtype "octet-
stream" is to be used in the case of uninterpreted binary
data, in which case the simplest recommended action is
to offer to write the information into a file for the user.
39. The two composite top-level media types are
1. Multipart: data consisting of multiple entities of
independent data types
2. Message :an encapsulated message.
