Internet and Web Concepts - PowerPoint PPT Presentation

Internet and web concepts l.jpg
Download
1 / 26

Internet and Web Concepts What is a URL? The Internet and the World Wide Web (subset) What is a browser? HTTP is? cs.uiuc.edu means… What is “hypertext?” What do we mean by client-server? Server Client HTTP Home Page Browser LAN Modem ISP KEY CONCEPTS

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

Internet and Web Concepts

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Internet and web concepts l.jpg

Internet and Web Concepts

  • What is a URL?

  • The Internet and the World Wide Web (subset)

  • What is a browser?

  • HTTP is?

  • cs.uiuc.edu means…

  • What is “hypertext?”

  • What do we mean by client-server?

CS 105 Spring 2006


Slide2 l.jpg

Server

Client

HTTP

Home Page

Browser

LAN

Modem

ISP

KEY CONCEPTS

CS 105 Spring 2006


Connecting to the internet l.jpg

Connecting to the Internet

ISP (Internet Service Provider)—connects to the Internet, and the user pays the hook-up fee and use charges. Examples: AOL, MSN, UIUC

  • Modem—Uses a phone line to reach a server

  • Cable — needs a cable modem (not really a modem!)

    Only if you have a T1 line do you have a direct connection to the Internet

CS 105 Spring 2006


Other means of connecting l.jpg

Other means of connecting

  • DSL (Digital Subscriber Line) — uses a DSL transceiver. You use your regular phone line, too.

  • ISDN connections use a special digital phone line that must be installed to your home by your local telephone company. They need a “Terminal Adapter”– also often called a “modem” (but it isn’t one)

  • Wireless Involves no wiring, just an antenna!

CS 105 Spring 2006


Programs communicate not computers l.jpg

Programs communicate, not computers

A program on one computer uses protocol software to contact a program on another computer– a protocol is an agreed format that computers on the Internet use to communicate.

  • E-mail protocols:

    • SMTP - Simple Mail Transfer Protocol

    • POP - Post Office Protocol

  • File transfer protocol: FTP

  • It is all based on…

CS 105 Spring 2006


Terminology l.jpg

Terminology

TCP/IP

Transmission Control Protocol/ Internet Protocol

TCP/IP is an agreed format that computers on the Internet use to communicate. Any computer that understands TCP/IP can connect to the Internet. Involves packets.


Voip internet telephony l.jpg

VOIP -- Internet Telephony

  • Make your phone calls over the Internet! Voice over Internet Protocol; using packet based networks instead of the standard telephones to send voice data

CS 105 Spring 2006


Converting a voice to digits l.jpg

Converting a voice to digits

  • Digital phones convert your voice into binary information (1s and 0s) and then compress the data

  • The person you talk to hears your voice after the 1s and 0s are changed back to sound

CS 105 Spring 2006


Slide9 l.jpg

  • Electronic messages are sent to your account and stored on a ___________________.

You send a message to someone. First it goes to a server

CS 105 Spring 2006


Slide10 l.jpg

  • Email software is later used to download messages from the __________ that is storing the message.

You receive email from the server, where it has been stored for you

CS 105 Spring 2006


Client relationship l.jpg

Client/________ Relationship

What is a server?

  • Some computers on the network offer services that others can access.

    • ftp server -- email

    • Yahoo, Google --

    • Library catalogues

Your query goes to the server

Server sends back information

CS 105 Spring 2006


Peer to peer l.jpg

Peer-to-Peer

  • Systems like KaZaa

  • Files held on individual machines rather than centralized server

CS 105 Spring 2006


Internet addressing ip addresses l.jpg

Internet Addressing -IP Addresses

  • Computer ports, called servers, connected to the Internet have unique addresses.

222.230.112.5

IP number is a 32-bit address in four parts, of 8 bits each, and therefore, in 8 bits you can only represent the numbers 0 to 255 (256 possible numbers). Thus this address is not possible:

299.230.112.5

222.230.112.6

222.230.112.7

CS 105 Spring 2006


Internet addressing domain names l.jpg

Internet Addressing -Domain names

  • These 4-part numbers are converted into easy-to-remember domain names.

uiuc.edu, google.com, eBay.com

google

amazon

CS 105 Spring 2006


Terminology15 l.jpg

Terminology

  • HTTP -- HyperText Transfer Protocol

    The protocol used for a web document (HTML).

    Example: http://www.uiuc.edu

  • HTTPS:

    • A HTTP protocol that provides for more secure web communications by including encryption methods.


Domain naming system l.jpg

Domain Naming System

  • provides mnemonic help in identifying sites

  • organizes the names of computers, subnetworks, and larger networks

  • reading left-to-right, information becomes more general

cs.uiuc.edu

educational site

University of Illinois @ Urbana-Champaign

Computer Science Department

CS 105 Spring 2006


The url l.jpg

http://www.cs.uiuc.edu/~roberta/

http:// ....... specifies Hypertext Transfer Protocol,

/ www.cs.uiuc.edu ......... Identifies location of web server

~ means bypass intermediate directories and go straight to the directory named roberta (~ is called a tilde)

index.html ........ is the name of the home page and will appear whether or not you type index.html!

The URL

CS 105 Spring 2006


Internet addressing url example l.jpg

Internet Addressing -URL Example

Secure

Protocol

https://netfiles.uiuc.edu/moor12/www/cluster/news.html

Folder

HTML

Document

Top Level

Domain

Student or Employee

CS 105 Spring 2006


Spam phishing where does this link take you l.jpg

Spam, Phishing – Where does this link take you?

CS 105 Spring 2006


Internet addressing top level domains l.jpg

Internet Addressing -Top level domains

  • You can find out who owns a domain name.

    • www.networksolutions.com/cgi-bin/whois/whois

uiuc.edu

google.com

whitehouse.gov

CS 105 Spring 2006


Top level domains l.jpg

Top Level Domains

.comCommercial businesses

.orgNon-profit organizations

.netNetwork services

.govGovernment agencies

.eduEducational institutions

.milMilitary

.intInternational

.nomFor individual users

.webWeb-based businesses

.AERO, .BIZ, .COOP, .INFO, .MUSEUM, .NAME, and .PRO

CS 105 Spring 2006


Common country domains l.jpg

Common Country Domains

  • .auAustralia

  • .fiFinland

  • .cn China

  • .ukUnited Kingdom

  • .usUnited States

  • .il Israel

  • .ch Switzerland

  • .mxMexico

CS 105 Spring 2006


Country ids l.jpg

Country IDs

CS 105 Spring 2006


Sample email address l.jpg

Sample Email Address

Jin45@uiuc.edu

username@hostname.com

“at”

Name of your ISP’s

host computer

Your userID

CS 105 Spring 2006


Using ph to find a person s email address l.jpg

Using ph to find a person’s email address

  • http://www.uiuc.edu/cgi-bin/ph

CS 105 Spring 2006


Terminology26 l.jpg

Terminology

  • HyperText Markup Language (HTML)

    A convention of codes used to display content such as words, pictures, etc. Without HTML code, a document would be unreadable by a Web browser. Right now, HTML is the Language of the World Wide Web, but the web is moving toXHTML

    Extensible Markup Language (XML) is the universal format for structured documents and data on the Web—it is compatible with XHTML but not with HTML. XML is built into the Windows XP operating system.


  • Login