Unit C and Buyer’s Guide

Pages C1 to C32

and

Pages 1 to 16

Internet History

Cyberspace – who coined the term?Internetwork or internet is a collection of two or more networksGrowth of Internet

1969 – ARPANET links four networks1985 – NSF expands ARPANET/education1986 – 2,000 host computers – Web, FTP, Usenet, IRC1990s – User-friendly software, 100 terabytes per week19 Degrees of Kevin Bacon?

Internet TerminologyNSPs (Network Service Providers) connect at NAPs (Network Access Points)Internet Backbone – a major set of communication links or routesISP – Internet Service ProviderConnection speed vs. transfer rateConnection types

Dial-up – POTS and modemCable Modem and DSL (Digital Subscriber Line)T1, T3, satellite, microwave, PDA, cell phone, etc.

Communications Software Protocols

A protocol is a set of rulesTCP/IP – primary protocol for Internet

• IP address = four dotted numbers between 0 and 255 May be static (semi-permanent) or dynamic (temporary)

• Routers forward information to/from IP addresses

SLIP and PPP – used for dial-up

PPTP and VPN (not in book)

CHAP (not in book)

HTTP is the protocol used to transmit Web pages

Hosts, Domains, and URLsMnemonic name = FQDN (domain name)

Ends in three-letter extension (.com, .gov, .edu)Extension indicates the top level domainCountries, states, and other organizations may have standard extensionsMaintained by InterNIC

A site is a virtual locationURL is the “address” of a document or site

index and .htm or .html defaultwww and http default with exceptions

The Six U

The World Wide Web is an Internet service that stores and provides information – but does it exist?Hypertext links – (usually) underlined text in a document which leads to another document or another portion of the same documentWeb portals and search engines

Web BrowsersA Web Browser is a multi-purpose program that allows the user to view Web pages on different types of servers

Microsoft Internet Explorer and Netscape NavigatorLynx (text) and Opera

Access Web pages by typing an IP address or a URL, or by linking from another pageCommon graphical features404, Bad Gateway, timeout and other errors

Scavenger Hunt, Anyone?Search engines are Web sites that search other Web pages for keywords or topics

Generic topic search engines (google.com, yahoo.com, msn.com, altavista.com, etc.)Bots or pricing services

• pricefarmer.com• bestbookbuys.com

2.2 liter 4-cylinder vs. 3.8 liter V8Dictionaries/encyclopedias can be search engines

Merriam Webster Onlinepcwebopedia.com and whatis.com

Electronic Mail

An e-mail message or letter is a document, created by a user with e-mail client software, (usually) sent to (at least) another user through (at least one) e-mail serverStore-and-forward = server stores messageGateways send mail across systemsE-mail address = networkID@domain.extFree or low-cost e-mail at hotmail.com, yahoo.com, angelfire.com, lycos.com, juno.com, many other sites and ISPsCc: vs Bcc:, mailing lists, return receipt, priority

Internet, World Wide Web, internet, intranet, extranet (huh?)

An internet (with a lowercase “i”) is composed of two or more connecting networks.The Internet (with a capital “I”) is a collection of local, regional, national, and international computer networks that are linked together to exchange data and distribute processing tasks.The World Wide Web is an Internet service in a hypertext environment. An intranet is a mini-internet designed primarily for use by employees exchanging data and information within an organization. An intranet ensures privacy by residing behind a firewall. An extranet is basically an intranet that provides various levels of accessibility to “outsiders” who have been assigned a username and password.

Multimedia on the WebStreaming media plays one segment of a file while receiving later segmentsIn-place multimedia (animated .gif) vs. overlayPlug-in – additional software that increases browser features and abilities (needed for Flash, RealPlayer, QuickTime)Push vs. Pull

Pull – information directly requested by the user at the current timePush – not directly requested by user right now

• May include desired but automated content (newsletter, webcast, stock quotes)

• May be intensely annoying (ads, INTERSTITIALS)

How to Start and Use Browsers on Campus

Demo only – no organized notes

Downloading and Uploading

Downloading means obtaining a file (usually FROM a server or remote site)

Uploading means to send a file (usually TO a server or remote site)

Can upload and download with FTP (WS-FTP)

Self-extracting files and zipped files

How to save a web page or element

Interacting online

Discussion groups – asynchronous, savedBulletin or message boards, WebCT

Chat group – synchronous, not saved

Safety measures

CCSN rules

Multiplayer gaming (e.g., MSN Zone)

HTM What the L?!?

HTML = Hyper Text Markup LanguageTags are instructions on how to display a page

Title and body - demo

Some tags require pairs – demo

Dynamic HTML, XML (.NET), Java, ActiveX

Ways to create HTML documentsBasic text editor – Notepad

Web authoring software – FrontPage, HomePage, Word

Publishing a Web Site

Design pointsPlanned links, templates, consistency

Colors for text and background

Copyrights, disclaimers, etc.

Identification, title, dates

Keep it up-to-date

Web host (may be an ISP)

Connecting to the Internet

Home connectionComputer, modem, telephone or other line

• Note that the book does not consider cable or DSL!

ISP

Necessary dial-up or other software• May include device drivers

• Requires a username and password to access ISP

Business and school connections usually do NOT use 56K modems and standard telephone lines!

Internet Scams, Hoaxes, and Misinformation

The Internet is now the fastest way to disseminate misinformation (people who won’t believe something in the traditional media -- which may have a wider audience -- will accept, spread, and perpetuate rumors from the Internet or e-mail, while being skeptical of TV or printed news; traditional media may also spread stories first reported on the Web)

Chain letters are (usually authorless) e-mails that request you to pass them onViruses (malicious, self-replicating programs) can be spread by the e-mail and downloaded filesRumors and semi-truthsQuestionable products and services

Buyer’s Guide pp 2-4

Bays provide areas in the computer case for installing devices

Internal – no opening to the outside (bracket)External – device is accessible outside the case

Port or expansion slot for printer or cardsHard Drives – EIDE, UltraATA, SCSI, DMACD-ROM speeds – advertised vs. average

Book math?

Buyer’s Guide pp 4, 6, 7

Cache is high-speed memory that gives the CPU more-rapid access to data

Level 1 (L1) – built into processor

Level 2 (L2) – separate chip, still faster than RAM

Benchmark – performance test for computersPassive vs. active matrix displays on notebooksPort replicators, PCMCIA, docking stationsHot-swapping for batteries and devices

Buyer’s Guide pp 8-14

Various mice (scrolling, trackball, IR)Keyboards (104, ergonomic, Braille)Printer types and considerations

Duty cycle = # of pages per monthReview cpi, dpi, ppm, CMYK

Sound cards, .wav, midi, MP3Modems, faxmodems, scannersReview backup typesReview user support optionsReview buying specifications

Buyer’s Guide pp 15-16Computer-use jobs have a majority of tasks that do not involve a computer (e.g., mechanic, clerk)Computer-related jobs utilize the unique abilities of computers in non-computer industries (e.g., graphic artist, architect)Computer-specific jobs would not exist without computers

Education usually involves a college degreeIndustry certification may be helpfulWork conditions and salaryOnline recruiting, résumés, research