IT_Chapter_2A

The Internet’s History

• 1969 – ARPANET

– Developed by the Department of Defense

– Connected universities and defense bases

• 1973 – ARPANET connects to Europe

The Internet’s History

• Mid-1980s – NSFNet

– Network between supercomputers

– Internet was the link to ARPANET

– No commercial traffic allowed

• 1990s

– ARPANET shut down

– NSFNet abandoned

– Commercial networks take over

Today and the Future

• 100,000 new web sites per month

• More than 50% of U.S. households online

• Access is available throughout the U.S.

• Eventually access will be global

The Internet’s Major Services

• The World Wide Web (WWW)

– Developed in 1993 by Tim-Berners Lee

– Allowed connection of documents

– Required a browser to read documents

• Electronic mail (e-mail)

– Instantaneous transmission of documents

The Internet’s Major Services

• News

– Often called newsgroups

– Electronic discussions on several topics

• File Transfer Protocol (FTP)

– Sends and receives files

The Internet’s Major Services

• Chat

– Public real time conversation

• Instant messaging

– Private real time conversation

• Peer-to-peer services

– Allows sharing of files among users

– Napster and Kazaa are examples

– Illegal to share copyrighted material

Accessing The Internet

• Internet Service Provider (ISP)

– Company that provides Internet access

• Dialup

– Connects to Internet through phone line

– Modem connects to the phone line

– Slow connection

Accessing The Internet

• High-speed access

– Connect through a special line

– 2 – 25 times faster than dialup

– DSL, Cable, T1 are common

Understanding the Internet

• The Internet allows accessing resources

• The Web simplifies the Internet

• The Web connects documents

– Hypertext creates links between documents

– Documents are stored on a web server

– HTTP delivers documents

Understanding the Internet

• Web site is a collection of documents

– Document is a web page

– Pages are published to the web

• Hypertext Markup Language

– Creates web pages

– Describes how pages should look

– Content enclosed in tags

– content

Understanding The Internet

• Browsers

– Read and translate the HTML

– Display web content

• Uniform Resource Locator (URL)

– Address of a web page

Understanding The Internet

• Helper applications

– Plug-ins

– Enhance a browser’s functionality

• Streaming audio and video

– Sends the file in small chunks

– Chunks downloaded while others play

Using a Browser And The WWW

• Browser starts on the home page

• Navigating the web

– Enter a URL in the browser

– Click a link

– Links are typically blue underlined words

– Image maps are picture links

• When finished, close the browser

Searching the Web

• The Web is unorganized

• Directories

– Categorize the Internet

• Search engines

– Find sites by keyword

Searching the Web

• Site searches

– Large sites have an internal search

• Metasearch sites

– Search several web sites at once

• Sponsored links

– Sites pay for better search results

Search Techniques

• Quote the exact phrase

• Use the keyword AND

• Use the keyword NEAR

• Avoid common words

• Use the site’s advanced tools